Add a work about code review to the readme.

Fix an initial-install dependency problem.

R=rsc
http://codereview.appspot.com/687041

Makefile

@@ -36,17 +36,23 @@ all:	install
 
 install:
 	cd proto && make install
+	cd compiler/descriptor && make install
+	cd compiler/plugin && make install
 	cd compiler && make install
 
 clean:
 	cd proto && make clean
 	cd compiler && make clean
+	cd compiler/descriptor && make clean
+	cd compiler/plugin && make clean
 	cd compiler/testdata && make clean
 	cd compiler/descriptor && make clean
 	cd compiler/plugin && make clean
 
 nuke:
 	cd proto && make nuke
+	cd compiler/descriptor && make nuke
+	cd compiler/plugin && make nuke
 	cd compiler && make nuke
 	cd compiler/testdata && make nuke
 	cd compiler/descriptor && make nuke

README

@@ -57,7 +57,14 @@ package.
 The generated files will be suffixed .pb.go.  See the Test code below
 for an example using such a file.
 
+This repository uses the same code review mechanism as Go, so
+if you wish to submit changes add the equivalent of these two lines
+to $GOROOT/src/pkg/goprotobuf.googlecode.com/hg/.hg/hgrc
 
+	[extensions]
+	codereview = $GOROOT/lib/codereview/codereview.py
+
+*where $GOROOT is the expanded text, such as /usr/foo/go*.
 
 The package comment for the proto library contains text describing
 the interface provided in Go for protocol buffers. Here is an edited