A FlagSet is an independent set of flags that may be used,
for example, to provide flag processing for subcommands
in a CLI.  The standard, os.Args-derived set of flags is a
global but non-exported FlagSet and the standard functions
are wrappers for methods of that FlagSet.

Allow the programmer to control whether the program
exits if there is a parse error.  For the default set, the behavior
remains to exit on error.

The handling of Usage is odd due to backward compatibility.

R=golang-dev, bradfitz, r, bradfitz
CC=golang-dev
https://golang.org/cl/4517092

R=rsc, iant
CC=golang-dev
https://golang.org/cl/4538083

A user pointed out that Go didn't work with their
corp proxy, always throwing 400 Bad Request errors.

Looking at the RFC 2616, Host is always required,
even with proxies.

The old code assumed that writing an absolute URL
in the first line of an HTTP request implied
that the Host header was no longer necessary.

Double-checked behavior with curl.

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/4539075

R=r
CC=golang-dev
https://golang.org/cl/4539073

R=iant
CC=golang-dev
https://golang.org/cl/4553051

Go keywords from Vim's syntax configuration file were used.
Issue Tracker Reference: http://code.google.com/p/go/issues/detail?id=1850

Fixes #1850.

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/4547054

Initially I wanted to minimise dependencies but it's become clear that
big int support in ASN.1 is a common need and that it should be part
of the core.

R=bradfitz
CC=golang-dev
https://golang.org/cl/4550063

This change adds a function for generating new Entities and inchoate
support for reserialising Entities.

R=bradfitz, r, bradfitz
CC=golang-dev
https://golang.org/cl/4551044

Fixes #1823

R=golang-dev, adg, robert.hencke
CC=golang-dev
https://golang.org/cl/4530054

R=golang-dev, iant
CC=golang-dev
https://golang.org/cl/4551051

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/4547056

This appears to have been a long-standing formatting bug.
The test cases has misformatted golden files.

Applied gofmt -w src misc .

Fixes #1839.

R=iant
CC=golang-dev
https://golang.org/cl/4515113

R=iant, iant2
CC=golang-dev
https://golang.org/cl/4515114

This enables customizing the behavior of formatters
with logic such as {"template"|import} or even
{Field1 Field2 "%.2f 0x%X"|printf}

Thanks to Roger Peppe for some debate on this.

R=golang-dev, r, r
CC=golang-dev
https://golang.org/cl/4536059

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/4539067

This code is extracted from crypto/rsa with
a few variables renamed and a comment fixed.

R=agl, rsc, agl
CC=golang-dev
https://golang.org/cl/4446068

It's documented as such, but it was never wired up
after Transport went in and Head was fixed.

If people don't want redirects, that's what RoundTripper/
Transport are for.  Or a custom redirect policy.

R=golang-dev, kevlar
CC=golang-dev
https://golang.org/cl/4526065

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/4535078

Before:
jpeg.BenchmarkEncodeRGBOpaque ... 23.29 MB/s
jpeg.BenchmarkEncodeRGBOpaque ... 23.27 MB/s
jpeg.BenchmarkEncodeRGBOpaque ... 23.17 MB/s

After:
jpeg.BenchmarkEncodeRGBOpaque ... 23.42 MB/s
jpeg.BenchmarkEncodeRGBOpaque ... 23.34 MB/s
jpeg.BenchmarkEncodeRGBOpaque ... 23.33 MB/s

R=rsc
CC=golang-dev
https://golang.org/cl/4538077

(DSA with SHA1, DSA with SHA256). Cleanup getSignatureFromOID
function.

R=agl, agl, rsc
CC=golang-dev
https://golang.org/cl/4530055

R=r, rsc
CC=golang-dev
https://golang.org/cl/4556041

R=golang-dev, mattn.jp, jcowgar, iant
CC=golang-dev
https://golang.org/cl/4535080

R=r
CC=golang-dev
https://golang.org/cl/4536065

R=rsc, r
CC=golang-dev
https://golang.org/cl/4536069

R=golang-dev, devon.odell
CC=golang-dev
https://golang.org/cl/4552051

R=ality, bradfitz, rsc, dsymonds, adg, qyzhai, dchest
CC=golang-dev
https://golang.org/cl/4536063

R=alex.brainman, rsc
CC=golang-dev, vcc.163
https://golang.org/cl/4532069

R=mattn.jp, rsc
CC=golang-dev
https://golang.org/cl/4528077

R=golang-dev, dave, rsc
CC=golang-dev
https://golang.org/cl/4553042

Also add grayscale test cases for image/decode_test.

R=r
CC=golang-dev
https://golang.org/cl/4526063

Fixes #1842.

R=r
CC=golang-dev
https://golang.org/cl/4517081

R=golang-dev, gary.burd, rsc
CC=golang-dev
https://golang.org/cl/4526062

Speeds up setting individual bits by ~75%, useful
when using big.Int as a bit set.

R=gri, rsc
CC=golang-dev
https://golang.org/cl/4538053

- add Data field to ast.Object
- for package objects, the Data field holds the package scope
- resolve several TODOs

R=rsc
CC=golang-dev
https://golang.org/cl/4538069

When GOMAXPROCS>1, the testing framework runs in parallel with the
test itself and may do a small number of allocations, so allow the
"noAllocs" condition to admit just a few.

Fixes #1782.

R=rsc
CC=golang-dev, rsc
https://golang.org/cl/4533041

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/4515092

R=golang-dev, bradfitz
CC=golang-dev
https://golang.org/cl/4539063

R=rsc
CC=golang-dev
https://golang.org/cl/4516057

Add seven methods to IP struct: IsUnspecified, IsLoopback,
IsMulticast, IsInterfaceLocalMulticast, IsLinkLocalMulticast,
IsLinkLocalUnicast and IsGlobalUnicast.

R=bradfitz, rsc
CC=golang-dev
https://golang.org/cl/4515083

Fixes #1830.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/4526060