add REVIEWERS and get_reviewer.pl script

Copied from linux kernel (where it is called MAINTAINERS and
get_maintainer.pl), with minimal changes to script (to recognize
mesa src tree rather than linux kernel src tree, and to avoid
accidentaly CC'ing Linus Torvalds on mesa patches), and slimmed
down MAINTAINER file syntax to recognize that we don't really have
subsystem "maintainers" in the same sense as the linux kernel (ie. no
different mailing lists and git trees per subsystem).

The main point is to automate slapping on the correct CC's for patches
via git's --cc-cmd feature, more than anything else.

I didn't attempt to fully populate the REVIEWERS file, by a long shot.
This is an opt-in system and anyone else can add their own entries.

To utilize:

  git send-email --cc-cmd ./scripts/get_reviewer.pl ...

or to configure it to be the default:

  git config sendemail.cccmd ./scripts/get_reviewer.pl

Signed-off-by: Rob Clark <robclark@freedesktop.org>

REVIEWERS

@@ -0,0 +1,106 @@
+Overview:
+
+	This file is similar in syntax (or more precisly a subset) of what is
+	used by the MAINTAINERS file in the linux kernel.  Some fields do not
+	apply, for example, in all cases, send patches to:
+
+		mesa-dev@lists.freedesktop.org
+
+	and in all cases the patchwork instance is:
+
+		https://patchwork.freedesktop.org/project/mesa/
+
+	The purpose is not exactly the same the MAINTAINERS file in the linux
+	kernel, as there are not official/formal maintainers of different
+	subsystems in mesa, but is meant to give an idea of who to CC for
+	various patches for review, and to allow the use of
+	scripts/get_reviewer.pl as git --cc-cmd.
+
+Usage:
+
+	When sending patches:
+
+		git send-email --cc-cmd ./scripts/get_reviewer.pl ...
+
+	Or to configure as default:
+
+		git config sendemail.cccmd ./scripts/get_reviewer.pl
+
+Descriptions of section entries:
+
+	R: Designated reviewer: FullName <address@domain>
+	   These reviewers should be CCed on patches.
+	F: Files and directories with wildcard patterns.
+	   A trailing slash includes all files and subdirectory files.
+	   F:	drivers/net/	all files in and below drivers/net
+	   F:	drivers/net/*	all files in drivers/net, but not below
+	   F:	*/net/*		all files in "any top level directory"/net
+	   One pattern per line.  Multiple F: lines acceptable.
+	N: Files and directories with regex patterns.
+	   N:	[^a-z]tegra	all files whose path contains the word tegra
+	   One pattern per line.  Multiple N: lines acceptable.
+	   scripts/get_maintainer.pl has different behavior for files that
+	   match F: pattern and matches of N: patterns.  By default,
+	   get_maintainer will not look at git log history when an F: pattern
+	   match occurs.  When an N: match occurs, git log history is used
+	   to also notify the people that have git commit signatures.
+
+Maintainers List (try to look for most precise areas first)
+
+Note: this is an opt-in system, I have not tried to add anyone who hasn't
+either asked me or sent a patch to add themselves.
+
+		-----------------------------------
+
+NIR
+R:	Jason Ekstrand <jason@jlekstrand.net>
+F:	src/compiler/nir/
+
+DOCUMENTATION
+R: Emil Velikov <emil.l.velikov@gmail.com>
+F: docs/
+F: doxygen/
+
+COMPATIBILITY HEADERS
+R: Emil Velikov <emil.l.velikov@gmail.com>
+F: include/c99*
+
+DRI LOADER
+R: Emil Velikov <emil.l.velikov@gmail.com>
+F: src/loader/
+
+GALLIUM LOADER
+R: Emil Velikov <emil.l.velikov@gmail.com>
+F: src/gallium/auxiliary/pipe-loader/
+F: src/gallium/auxiliary/target-helpers/
+
+GALLIUM TARGETS
+R: Emil Velikov <emil.l.velikov@gmail.com>
+F: src/gallium/targets/
+
+AUTOCONF BUILD
+R: Emil Velikov <emil.l.velikov@gmail.com>
+F: configure.ac
+F: */Automake.inc
+F: */Makefile.*am
+F: */Makefile.sources
+
+SCONS BUILD
+F: scons/
+F: */SConscript*
+F: */Makefile.sources
+
+ANDROID BUILD
+R: Emil Velikov <emil.l.velikov@gmail.com>
+F: CleanSpec.mk
+F: */Android.*mk
+F: */Makefile.sources
+
+WAYLAND EGL SUPPORT
+R: Daniel Stone <daniels@collabora.com>
+F: src/egl/wayland/*
+F: src/egl/drivers/dri2/platform_wayland.c
+
+FREEDRENO
+R:	Rob Clark <robclark@freedesktop.org>
+F:	src/gallium/drivers/freedreno/