Fixes #3490.

R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/6040046

       also gives clear error when bsdthread_register fails on Darwin
       Fixes #2992.

R=rsc, krautz
CC=golang-dev
https://golang.org/cl/5966067

This will allow us to properly thread "R=..." mails at a later time.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6135053

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6135052

R=golang-dev, bradfitz, r
CC=golang-dev
https://golang.org/cl/6128054

Fixes #3577

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6137054

Re-submitting previously reverted change 160ec5506cb7.

R=golang-dev, r, r
CC=golang-dev
https://golang.org/cl/6129052

In CL 6127051, nigeltao suggested that further gains
were possible by improving the performance of flate.
This CL adds a set of benchmarks (based on compress/lzw)
that can be used to judge any future improvements.

R=nigeltao
CC=golang-dev
https://golang.org/cl/6128049

Fix auth requirements for /gc endpoint too.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6133049

This closes any internal descriptors (pipes, etc) that Cmd.Start() had
opened before it failed.

Fixes #3468.

R=golang-dev, iant, bradfitz
CC=golang-dev
https://golang.org/cl/5986044

R=golang-dev, bsiegert, r
CC=golang-dev
https://golang.org/cl/6127056

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6128044

In resolving 3507, the fix had to be applied individually to
the four *Conn types, tcp, udp, rawip and unix, due to the
duplicate code in each Conn type.

This CL consolidates the common net.Conn methods that all four
*Conn types implement into a base conn type.

Pros:
* The fix for 3507 would have only needed to be applied to one
method. Further improvements, such as possibly removing the
c.fd != nil check in c.ok(), would benefit from this CL.
* Nearly 300 lines removed from the net package.
* The public interface and documentation are not changed.
* I think this is an excellent example of the power of embedding.

Cons:
* The net package is already distributed over many files, this
CL adds another place to look.
* The fix for 3507 was a total of 16 lines changed, this follow
up CL could be considered to be an overreaction as new Conn types
are unlikely to be added in the near future.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6098047

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6131044

This is live at http://gocodereview.appspot.com/.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6134043

Paletted, RGBA.

benchmark                       old ns/op    new ns/op    delta
BenchmarkDecodeGray               3681144      2536049  -31.11%
BenchmarkDecodeNRGBAGradient     12108660     10020650  -17.24%
BenchmarkDecodeNRGBAOpaque       10699230      8677165  -18.90%
BenchmarkDecodePaletted           2562806      1458798  -43.08%
BenchmarkDecodeRGB                8468175      7180730  -15.20%

benchmark                        old MB/s     new MB/s  speedup
BenchmarkDecodeGray                 17.80        25.84    1.45x
BenchmarkDecodeNRGBAGradient        21.65        26.16    1.21x
BenchmarkDecodeNRGBAOpaque          24.50        30.21    1.23x
BenchmarkDecodePaletted             25.57        44.92    1.76x
BenchmarkDecodeRGB                  30.96        36.51    1.18x

$ file $GOROOT/src/pkg/image/png/testdata/bench*
benchGray.png:           PNG image, 256 x 256, 8-bit grayscale, non-interlaced
benchNRGBA-gradient.png: PNG image, 256 x 256, 8-bit/color RGBA, non-interlaced
benchNRGBA-opaque.png:   PNG image, 256 x 256, 8-bit/color RGBA, non-interlaced
benchPaletted.png:       PNG image, 256 x 256, 8-bit colormap, non-interlaced
benchRGB.png:            PNG image, 256 x 256, 8-bit/color RGB, non-interlaced

R=r
CC=golang-dev
https://golang.org/cl/6127051

Both of these have replacements.

R=golang-dev, r, rsc, r, adg
CC=golang-dev
https://golang.org/cl/5979046

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/6117063

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6117066

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6115056

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6125048

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6123055

The new logic is "use go1 if it's there, otherwise no tag."
Nothing needs to say "I require go1.0.1", and I want to
preserve some flexibility in defining what tags mean.

Right now (before go1.0.1) there is only one possible tag,
"go1", and I'd like to keep it that way.

R=golang-dev, bradfitz, r, adg
CC=golang-dev
https://golang.org/cl/6112060

Now that Go will no longer work on OpenBSD versions prior to 5.1,
remove the sysctl workaround that was needed for 5.0 and earlier.

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/6116050

1. Readdirnames was erroneously returning an
   empty slice on every invocation.

2. The logic for determining which files to
   close before exec was incorrect.  If the
   set of files to be kept open (provided by
   the caller) did not include the files
   opened at startup, those files would be
   accidentally closed.

I also cleaned up readdupdevice while I was
in the vicinity.

R=golang-dev, seed, rsc
CC=golang-dev
https://golang.org/cl/6016044

I also added some debugging code that's turned
on with -xx.

Fixes #3392.

R=rsc, lvd
CC=golang-dev
https://golang.org/cl/5909058

Fixes #3569.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6116055

RGBA.

R=adg, r, bsiegert
CC=golang-dev
https://golang.org/cl/6119054

R=adg, dsymonds
CC=golang-dev
https://golang.org/cl/5849053

Clean up flow of control.

Handle </tbody>, </tfoot>, and </thead>.

Pass 5 additional tests.

R=nigeltao
CC=golang-dev
https://golang.org/cl/6117057

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/6127050

R=adg
CC=golang-dev
https://golang.org/cl/6127048

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/6114053

Fixes #3538

R=golang-dev, adg, rsc
CC=golang-dev
https://golang.org/cl/6117058

Fixes #3562

R=golang-dev, adg, rsc
CC=golang-dev
https://golang.org/cl/6119051

Switch from using the rfork() syscall on OpenBSD, to the __tfork()
syscall.  The __tfork() syscall is the preferred way of creating
system threads and the rfork() syscall has recently been removed.

Note: this will break compatibility with OpenBSD releases prior to 5.1.

R=golang-dev, bradfitz, devon.odell, rsc
CC=golang-dev
https://golang.org/cl/6037048

collation table. At this moment, it only implements the generation of
a root table.

R=r
CC=golang-dev
https://golang.org/cl/6039047

context for change lists of lower-level types. The public APIs are defined
in builder.go and collate.go. Type table is the glue between the lower and
higher level code and might be a good starting point for understanding the
collation code.

R=r, r
CC=golang-dev
https://golang.org/cl/5999053

The trie code looks a lot like the trie in exp/norm. It uses different
types, however.  Also, there is only a lookup for []byte and the unsafe
lookup methods have been dropped, as well as sparse mode.
There is now a method for generating a trie. To output Go code, one now needs
to first generate a trie and then call print() on it.

R=r, r, mpvl
CC=golang-dev
https://golang.org/cl/5966064

(see http://www.unicode.org/reports/tr10/).

R=r, r
CC=golang-dev
https://golang.org/cl/5981048