Fixes #1555.

R=rsc, bradfitzgo
CC=golang-dev
https://golang.org/cl/4284047

R=rsc, dsymonds
CC=golang-dev
https://golang.org/cl/4278044

Also don't serialize empty headers.

R=dsymonds, rsc
CC=golang-dev
https://golang.org/cl/4275045

R=iant, dho
CC=golang-dev
https://golang.org/cl/4286044

R=rsc
CC=golang-dev
https://golang.org/cl/4275043

The loop always makes an extra system call.  It only makes a
difference if more than 100 goroutines started waiting for
something to happen on a network file descriptor since the
last time the pipe was drained, which is unlikely since we
will be woken up the first time a goroutine starts waiting.
If we don't drain the pipe this time, we'll be woken up again
right away and can drain again.

R=rsc
CC=golang-dev
https://golang.org/cl/4275042

Add a benchmark.
BenchmarkEndToEndPipe gives 14.3microseconds/op before,
13.1microseconds/op after, or about 76e3 round trips per second
through the kernel.
With a bytes buffer, and therefore no system calls for I/O, the
numbers go to 7.3microseconds/op, or about 137e3 round trips
per second.

R=rsc
CC=golang-dev
https://golang.org/cl/4279045

- removed uses of global variables
- minor cleanups

R=r
CC=golang-dev
https://golang.org/cl/4277044

R=rsc
CC=golang-dev
https://golang.org/cl/4278043

R=r, rsc1
CC=golang-dev
https://golang.org/cl/4291042

R=golang-dev, iant, r
CC=golang-dev
https://golang.org/cl/4239079

R=r, dsymonds
CC=golang-dev
https://golang.org/cl/4273045

R=golang-dev, rog, bradfitzwork, r
CC=golang-dev
https://golang.org/cl/4243072

R=ken2, ken3
CC=golang-dev
https://golang.org/cl/4259064

R=gri, r, r2
CC=golang-dev
https://golang.org/cl/4249065

Transport.Do -> RoundTripper.RoundTrip

This makes way for a subsequent CL to export the
currently private RoundTripper implementation
as struct Transport.

R=rsc, r
CC=golang-dev
https://golang.org/cl/4286043

First version. Handles scope analysis only at the
moment.

R=rsc, r, eds
CC=golang-dev
https://golang.org/cl/4259065

Fixes #1602

R=rsc, petar-m
CC=golang-dev
https://golang.org/cl/4284043

This makes it possible to build a package twice
and get the same bytes both times.

R=r, dsymonds, r2
CC=golang-dev
https://golang.org/cl/4248077

.hgtags, release.html: tag current weekly as release.r56

R=r, rsc
CC=golang-dev
https://golang.org/cl/4281041

Make ReadAll use the same mechanism as ReadFile.

R=r
CC=golang-dev
https://golang.org/cl/4279041

Print a newline after each map entry;
similar to the style used for slices
and structs.

R=r, r2
CC=golang-dev
https://golang.org/cl/4274042

Also removed a TODO (AST nodes have been restructured a while ago).

R=r
CC=golang-dev
https://golang.org/cl/4245077

Functionality was only present for
debuggging and now is available in
gocheck where is makes more sense.

R=rsc
CC=golang-dev
https://golang.org/cl/4239078

Fixes #1601.

R=rsc
CC=golang-dev
https://golang.org/cl/4249070

All tests are now localhost only.

R=rsc
CC=golang-dev
https://golang.org/cl/4271042

More reliable.

R=rsc
CC=golang-dev
https://golang.org/cl/4249068

ResponseWriter.RemoteAddr() string -> Request.RemoteAddr string
ResponseWriter.UsingTLS() bool -> Request.TLS *tls.ConnectionState

R=rsc, bradfitzwork
CC=gburd, golang-dev
https://golang.org/cl/4248075

(No code changes, Americanization only.)

R=rsc, bradfitzwork
CC=golang-dev
https://golang.org/cl/4250075

R=agl, agl1
CC=golang-dev, rsc
https://golang.org/cl/4248078

R=rsc, bradfitzwork
CC=golang-dev
https://golang.org/cl/4244066

R=rsc
CC=golang-dev
https://golang.org/cl/4240104

R=rsc, cw
CC=golang-dev
https://golang.org/cl/4253073

by bogus data, or are in any case recoverable.

Fixes #1598.

R=rsc
CC=golang-dev
https://golang.org/cl/4240101

R=adg
CC=golang-dev
https://golang.org/cl/4248076

Add discussion of getters.
Add example using a map as a set.

R=golang-dev, gri, adg, iant
CC=golang-dev
https://golang.org/cl/4240100

This is to make it easier to support Solaris syslog.  On
Solaris syslog messages are sent via STREAMS using putmsg to
/dev/conslog.  The putmsg call uses a a control buffer of type
log_cdtl and a data buffer which is the message, and it is in
general a big mess.  This CL just splits out the Unix domain
support so that Solaris can use a different mechanism.  I do
not propose to implement the Solaris support today.  This
split will make it possible for gccgo to just call the libc
function for now.

R=r, rsc
CC=golang-dev
https://golang.org/cl/4261061

The Flush functionality wasn't removed, but now you have
to test if your ResponseWriter is also a Flusher:

func ServeHTTP(rw http.ResponseWriter, req *http.Request) {
   if f, ok := rw.(http.Flusher); ok {
       f.Flush()
   }
}

R=rsc, bradfitzwork
CC=gburd, golang-dev
https://golang.org/cl/4239077

Was a mysterious holdover from an attempt to fix a problem
long-resolved, I think.

R=rsc, r2
CC=golang-dev
https://golang.org/cl/4243066

When writing custom scanners, I found that
Token itself was rarely useful, as I did not always
want to stop at white space. This change makes
it possible to stop at any class of characters
while reusing the buffer within State.
(also fix a bug in Token)

R=r, r2
CC=golang-dev
https://golang.org/cl/4243055