CONTRIBUTING.md: add message about pull requests

Change-Id: Id3f1f8e16bbbaa99ead6d227c0b3dade9727ec61
Reviewed-on: https://plan9port-review.googlesource.com/1090
Reviewed-by: Russ Cox <rsc@swtch.com>
devdraw: fix title and "open in top" on OS X

On OSX 10.10, when you open an application that depends on devdraw, the
title bar only shows the first letter of the application's name. The
patch sets a default title as soon as the window is created, which
fixes this issue.

On OSX 10.10, when you open an application that depends on devdraw, this
application is opened in top of other windows, however the menu bar is
not updated. The patch calls topwin() at the end of makewin() in
src/cmd/devdraw/cocoa-screen.m .

Change-Id: Ie036928b5574c8df20ad8b2b54047e2f7a22bb41
Reviewed-on: https://plan9port-review.googlesource.com/1091
Reviewed-by: Russ Cox <rsc@swtch.com>
libdraw, libframe, acme: fix, guard against inverted range in textsetselect

Credit to Roi Martin <jroi.martin@gmail.com> for noticing that
libdraw was being passed a negative string length and for finding the
sequence of keystrokes that make acme do it reproducibly.

Change-Id: If3f3d04a25c506175f740d3e887d5d83b5cd1bfe
Reviewed-on: https://plan9port-review.googlesource.com/1092
Reviewed-by: Russ Cox <rsc@swtch.com>
install.txt: regenerate (9 man 1 intro >install.txt)

Change-Id: I80331732ce955d5b025a3552d15c6d7494752bf6
Reviewed-on: https://plan9port-review.googlesource.com/1093
Reviewed-by: Russ Cox <rsc@swtch.com>
9pfuse: Disable glibc workaround for O_LARGEFILE on ARM

9pfuse fails on ARM when O_LARGEFILE is supported.
glibc does define O_LARGEFILE properly on ARM,
and the value is different than what that this workaround suggests,
causing it to wrongly detect bad flags.

Change-Id: I02b0cc222ca7785c4b1739c3df3caa17cf7bc265
Reviewed-on: https://plan9port-review.googlesource.com/1094
Reviewed-by: Russ Cox <rsc@swtch.com>
fontsrv: disable X11 hinting

Discussion at:
https://groups.google.com/d/topic/plan9port-dev/L7RVkXPmrdY/discussion
https://github.com/9fans/plan9port/pull/7

Change-Id: I4f3a6791436120388ad8798e519f5e8473dd9306
Reviewed-on: https://plan9port-review.googlesource.com/1095
CONTRIBUTING.md: fix link to codereview(1)

Change-Id: I259a397398776bf9a172f1f4ed69e608166f35fb
Reviewed-on: https://plan9port-review.googlesource.com/1097
Reviewed-by: Russ Cox <rsc@swtch.com>
Add copy, cut, paste, and undo via ^c, ^x, ^v, and ^z.