Add release notes to the distribution.

This also adds a hook in the Makefile I can use to automatically
include pointers to documentation for older releases when updating
the pages at http://kernel.org/pub/software/scm/git/docs/.

Signed-off-by: Junio C Hamano <junkio@cox.net>

Documentation/install-webdoc.sh

@@ -2,7 +2,7 @@
 
 T="$1"
 
-for h in *.html *.txt howto/*.txt howto/*.html
+for h in *.html *.txt howto/*.txt howto/*.html RelNotes-*.txt
 do
 	if test -f "$T/$h" &&
 	   diff -u -I'Last updated [0-9][0-9]-[A-Z][a-z][a-z]-' "$T/$h" "$h"