Fixes #2652.

R=adg, rsc
CC=golang-dev
https://golang.org/cl/5516045

R=golang-dev
CC=golang-dev
https://golang.org/cl/5540062

Duplicated fields from URL were dropped so that its behavior
is simple and expected when being stringified and when being
operated by packages like http. Most of the preserved fields
are in unencoded form, except for RawQuery which continues to
exist and be more easily handled via url.Query().

The RawUserinfo field was also replaced since it wasn't practical
to use and had limitations when operating with empty usernames
and passwords which are allowed by the RFC. In its place the
Userinfo type was introduced and made accessible through the
url.User and url.UserPassword functions.

What was previous built as:

        url.URL{RawUserinfo: url.EncodeUserinfo("user", ""), ...}

Is now built as:

        url.URL{User: url.User("user"), ...}

R=rsc, bradfitz, gustavo
CC=golang-dev
https://golang.org/cl/5498076

R=rsc
CC=golang-dev
https://golang.org/cl/5543065

        5l/asm.c: code in line 311-319 has already outputed segtext.sect->next;

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5532048

Fixes #2044.

R=golang-dev
CC=golang-dev
https://golang.org/cl/5541056

Fixes #2598.

R=golang-dev, ality, minux.ma, mpimenov, rsc
CC=golang-dev
https://golang.org/cl/5510043

The Makefiles will go away soon.

R=agl
CC=golang-dev
https://golang.org/cl/5544081

R=golang-dev
TBR=adg
CC=golang-dev
https://golang.org/cl/5545068

Until a RFC 6265 jar lands, Request.AddCookie() will work incorrectly.

Fixes #2692

R=bradfitz, rsc
CC=golang-dev, r
https://golang.org/cl/5544069

R=golang-dev, jsing
CC=golang-dev
https://golang.org/cl/5528106

R=dave, agl, agl
CC=golang-dev
https://golang.org/cl/5494057

R=golang-dev, dvyukov
CC=golang-dev
https://golang.org/cl/5540059

Fixes #2712.

R=golang-dev, dsymonds
CC=golang-dev, mpimenov
https://golang.org/cl/5543062

Fixes #2710.

R=golang-dev, dsymonds
CC=golang-dev
https://golang.org/cl/5541066

Fixes #2708.

R=golang-dev, bradfitz
CC=golang-dev, mpimenov
https://golang.org/cl/5543060

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5545062

R=nigeltao, dsymonds, adg
CC=golang-dev
https://golang.org/cl/5544073

R=golang-dev, dave, agl
CC=golang-dev
https://golang.org/cl/5533081

(Google CLA)

R=rsc, bradfitz
CC=golang-dev
https://golang.org/cl/5544072

R=golang-dev
CC=golang-dev
https://golang.org/cl/5539064

R=golang-dev, dsymonds, r, n13m3y3r
CC=golang-dev
https://golang.org/cl/5543049

R=golang-dev
CC=golang-dev
https://golang.org/cl/5542050

R=golang-dev
CC=golang-dev
https://golang.org/cl/5528102

R=golang-dev
CC=golang-dev
https://golang.org/cl/5541060

The terminal code in exp/terminal was forked from the code in exp/ssh.
This change removes the duplicated code from exp/ssh in favour of
using exp/terminal.

R=rsc
CC=golang-dev
https://golang.org/cl/5375064

allowed by RFC 6265 sec 5.2.2.

R=golang-dev, adg
CC=golang-dev
https://golang.org/cl/5533083

This CL revises existing platform-dependent default socket
options to make it possible to accomodate multiple multicast
datagram listeners on a single service port.

Also removes unnecessary SO_REUSEADDR, SO_REUSEPORT socket
options from unicast datagram sockets by default.

Fixes #1692.

R=devon.odell, alex.brainman, rsc
CC=golang-dev
https://golang.org/cl/5538052

Fixes #2595.

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/5544068

        The strconv package has removed Atob, AtoF{64,32} and Ftoa.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5540057

Fixes #2672.

R=golang-dev, lvd
CC=golang-dev, remy
https://golang.org/cl/5543058

(This was missing in the last change because I uploaded it from the
wrong machine.)

Large pastes previously misbehaved because the code tried reading from
the terminal before checking whether an line was already buffered.
Large pastes can cause multiples lines to be read at once from the
terminal.

R=bradfitz
CC=golang-dev
https://golang.org/cl/5542049

exp/proxy provides client support for tunneling connections through
various proxies.

This is an initial, incomplete sketch of the code to lay down an
API.

R=golang-dev, r, r, bradfitz, rsc
CC=golang-dev
https://golang.org/cl/5490062

R=golang-dev, dave, minux.ma
CC=golang-dev
https://golang.org/cl/5545044

R=golang-dev
CC=golang-dev
https://golang.org/cl/5539061

R=golang-dev, gri
CC=golang-dev
https://golang.org/cl/5528101

R=golang-dev, bradfitz, gri
CC=golang-dev
https://golang.org/cl/5539059

Fixes #2694

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5541057

R=golang-dev, r, bradfitz
CC=golang-dev
https://golang.org/cl/5543056

Also verified in external test suite that this fixes MySQL
resource exhaustion problems, and also exposed a double-free
bug in the gosqlite3 driver (where gosqlite3 either got lucky
before, or was working around this bug)

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/5544057