cmd/go: update doc.go

R=golang-dev, adg
CC=golang-dev
https://codereview.appspot.com/7279047
net/http: fix when server deadlines get extended

Deadlines should be extended at the beginning of
a request, not at the beginning of a connection.

Fixes issue 4676

R=golang-dev, fullung, patrick.allen.higgins, adg
CC=golang-dev
https://codereview.appspot.com/7220076
syscall: regenerate ztype files for linux

This CL adds TCPInfo struct to linux/386,arm.
It's already added to linux/amd64.

Note that not sure the reason but cgo godefs w/ latest gcc
translates a flexible array member in structures correctly,
handles it as a non-incomplete, non-opaque type, on Go 1.
This CL reverts such changes by hand for the Go 1 contract.

R=minux.ma, bradfitz, rsc
CC=golang-dev
https://codereview.appspot.com/7197046
net/http: add Next Protocol Negotation upgrade support to the Server

This provides the mechanism to connect SPDY support to the http
package, without pulling SPDY into the standard library.

R=rsc, agl, mikioh.mikioh
CC=golang-dev
https://codereview.appspot.com/7287045
syscall: fix marshaling of stat messages on Plan 9

The order of the Qid fields was reversed. Mea culpa.

R=seed
CC=golang-dev
https://codereview.appspot.com/7231062
cmd/gc: fix escape analysis

If the analysis reached a node twice, then the analysis was cut off.
However, if the second arrival is at a lower depth (closer to escaping)
then it is important to repeat the traversal.

The repeating must be cut off at some point to avoid the occasional
infinite recursion. This CL cuts it off as soon as possible while still
passing all tests.

Fixes issue 4751.

R=ken2
CC=golang-dev, lvd
https://codereview.appspot.com/7303043
path/filepath: document that Walk does not follow symlinks

Fixes issue 4759.

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7304043
net/http: fix Server blocking after a Handler's Write fails

If a Handle's Write to a ResponseWriter fails (e.g. via a
net.Conn WriteDeadline via WriteTimeout on the Server), the
Server was blocking forever waiting for reads on that
net.Conn, even after a Write failed.

Instead, once we see a Write fail, close the connection,
since it's then dead to us anyway.

Fixes issue 4741

R=golang-dev, adg
CC=golang-dev
https://codereview.appspot.com/7301043
archive/tar: small simplification using FileMode.

R=golang-dev, bradfitz
CC=golang-dev
https://codereview.appspot.com/7305043