valadoc-git: use fixed date and specific git commit.

srcpkgs/valadoc-git/template

@@ -1,6 +1,6 @@
 # Template file for 'valadoc-git'
 pkgname=valadoc-git
-version="$(date -u +%Y%m%d)"
+version=20130128
 revision=1
 nofetch=yes
 noextract=yes
@@ -18,6 +18,7 @@ do_fetch() {
 	local url="git://git.gnome.org/valadoc"
 	msg_normal "Fetching source from $url ...\n"
 	git clone ${url} ${pkgname}-${version}
+	cd ${pkgname}-${version} && git checkout df9357f508feeff9e7730a7124b7d700829a5951
 }
 
 pre_configure() {