This matches the real ResponseWriter behavior.

R=rsc
CC=golang-dev
https://golang.org/cl/4291048

R=agl, agl1
CC=golang-dev
https://golang.org/cl/4297041

This reduces the number of writes by 2 (1 client, 1 server) on each round trip.
A simple test shows 24% higher throughput.

R=rsc
CC=golang-dev
https://golang.org/cl/4279057

R=golang-dev, r, dsymonds, rsc1
CC=golang-dev
https://golang.org/cl/4277046

R=ken2
CC=golang-dev
https://golang.org/cl/4279053

This change records more metadata about what
influenced the creation of the object file.
Specifically, if a package imports, say, "fmt" but does not
need to describe any fmt types in its own export data,
that package's object file did not mention the dependency
on "fmt" before.  Now it does.

Listing the import is purely informational.
It has no effect on which files are opened or consulted
when importing a package.

Import lines are marked indirect when they are needed
to explain the API but were not imported directly.
For example http imports crypto/tls and exports
a struct with a field of type tls.ConnectionState,
which contains an x509.Certificate.  Since http does
not import x509 but needs to explain the x509.Certificate
type in its export data, the import of x509 is marked
as indirect.  These import lines were always present;
marking them with the indirect comment makes clear
which were imported directly and which are incidental.

R=ken2
CC=golang-dev
https://golang.org/cl/4295048

R=golang-dev, dfc, rsc1, rsc
CC=golang-dev
https://golang.org/cl/4274048

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