doc: missing words and letters in release notes

Change-Id: Ica7f2a000eb1d89d5b02cb8c6f1596ddc04bfb26
Reviewed-on: https://go-review.googlesource.com/18890Reviewed-by: Ian Lance Taylor <iant@golang.org>

doc/go1.6.html

@@ -118,10 +118,10 @@ instead of generated from <a href="/cmd/yacc/">yacc</a>.
 </p>
 
 <p>
-The compiler, linker, and <code>go</code> command have new flag <code>-msan</code>,
+The compiler, linker, and <code>go</code> command have a new flag <code>-msan</code>,
 analogous to <code>-race</code> and only available on linux/amd64,
 that enables interoperation with the <a href="http://clang.llvm.org/docs/MemorySanitizer.html">Clang MemorySanitizer</a>.
-Such interoperation useful mainly for testing a program containing suspect C or C++ code.
+Such interoperation is useful mainly for testing a program containing suspect C or C++ code.
 </p>
 
 <p>
@@ -588,7 +588,7 @@ Also in the <a href="/pkg/encoding/asn1/"><code>encoding/asn1</code></a> package
 The <a href="/pkg/encoding/base64"><code>encoding/base64</code></a> package's
 <a href="/pkg/encoding/base64/#Decoder"><code>Decoder</code></a> has been fixed
 to process the final bytes of its input. Previously it processed as many four-byte tokens as
-possible but ignore the remainder, up to three bytes.
+possible but ignored the remainder, up to three bytes.
 The <code>Decoder</code> therefore now handles inputs in unpadded encodings (like
 <a href="/pkg/encoding/base64/#RawURLEncoding">RawURLEncoding</a>) correctly,
 but it also rejects inputs in padded encodings that are truncated or end with invalid bytes,
@@ -631,13 +631,13 @@ In previous releases, the argument to <code>*</code> was required to have type <
 Also in the <a href="/pkg/fmt/"><code>fmt</code></a> package,
 <a href="/pkg/fmt/#Scanf"><code>Scanf</code></a> can now scan hexadecimal strings using %X, as an alias for %x.
 Both formats accept any mix of upper- and lower-case hexadecimal.
-<a href="golang.org/x/13585">TODO: Keep?</a>
+<a href="https://golang.org/issues/13585">TODO: Keep?</a>
 </li>
 
 <li>
 The <a href="/pkg/image/"><code>image</code></a>
 and
-The <a href="/pkg/image/color/"><code>image/color</code></a> packages
+<a href="/pkg/image/color/"><code>image/color</code></a> packages
 add
 <a href="/pkg/image/#NYCbCrA"><code>NYCbCrA</code></a>
 and
@@ -731,10 +731,11 @@ Second, the
 <code>Expect:</code> <code>100-continue</code> header (see
 <a href="/pkg/http/#Transport"><code>Transport.ExpectContinueTimeout</code></a>).
 Third, there are
-<a href="/pkg/net/http/#pkg-constants">four new error codes</a> from RFC 6585:
+<a href="/pkg/net/http/#pkg-constants">five new error codes</a> from RFC 6585:
 <code>StatusPreconditionRequired</code> (428),
 <code>StatusTooManyRequests</code> (429),
 <code>StatusRequestHeaderFieldsTooLarge</code> (431),
+<code>StatusUnavailableForLegalReasons</code> (451)),
 and
 <code>StatusNetworkAuthenticationRequired</code> (511).
 Fourth, the implementation and documentation of
@@ -825,7 +826,7 @@ In the <a href="/pkg/os/exec/"><code>os/exec</code></a> package,
 <a href="/pkg/os/exec/#Cmd.Output"><code>Output</code></a> method continues to return an
 <a href="/pkg/os/exec/#ExitError"><code>ExitError</code></a> when a command exits with an unsuccessful status.
 If standard error would otherwise have been discarded,
-the returned <code>ExitError</code> now holds a prefix
+the returned <code>ExitError</code> now holds a prefix and suffix
 (currently 32 kB) of the failed command's standard error output,
 for debugging or for inclusion in error messages.
 The <code>ExitError</code>'s