Updated all plugins that are non-forked. Added some new plugins.

Added update_plugins.py which can fetch new plugins from GitHub.

New plugins added: zencoding, vim-indent-object, taglist, nginx.vim

sources_non_forked/snipmate-snippets/objc/forarray.snippet

@@ -0,0 +1,7 @@
+unsigned int	${1:object}Count = [${2:array} count];
+
+for (unsigned int index = 0; index < $1Count; index++)
+{
+	${3:id}	$1 = [$2 $1AtIndex:index];
+	${4}
+}