Go support for protocol buffers.

Consists of a compiler plugin and the support library, all written in Go.

This is a complete implementation except for:
  - Extensions in the plugin
    - coming soon
    - support is already in the library
  - Services (RPC)
    - needs an external definition to honor before supporting.
  - Insertion points in the plugin
    - may come

R=rsc, dsymonds1, ken2
CC=golang-dev
http://codereview.appspot.com/676041
diff --git a/Make.protobuf b/Make.protobuf
new file mode 100644
index 0000000..d307aa0
--- /dev/null
+++ b/Make.protobuf
@@ -0,0 +1,46 @@
+# Go support for Protocol Buffers - Google's data interchange format
+#
+# Copyright 2010 Google Inc.  All rights reserved.
+# http://code.google.com/p/goprotobuf/
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are
+# met:
+#
+#     * Redistributions of source code must retain the above copyright
+# notice, this list of conditions and the following disclaimer.
+#     * Redistributions in binary form must reproduce the above
+# copyright notice, this list of conditions and the following disclaimer
+# in the documentation and/or other materials provided with the
+# distribution.
+#     * Neither the name of Google Inc. nor the names of its
+# contributors may be used to endorse or promote products derived from
+# this software without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+# A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+# OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+# LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+# Includable Makefile to add a rule for generating .pb.go files from .proto files
+# (Google protocol buffer descriptions).
+# Typical use if myproto.proto is a file in package mypackage in this directory:
+#
+#	include $(GOROOT)/src/Make.$(GOARCH)
+#	TARG=mypackage
+#	GOFILES=\
+#		myproto.pb.go
+#
+#	include $(GOROOT)/src/Make.pkg
+#	include $(GOROOT)/src/pkg/goprotobuf.googlecode.com/hg/Make.proto
+
+%.pb.go:	%.proto
+	protoc --go_out=. $<
+