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/vim-snippets/snippets/rst.snippets

@@ -0,0 +1,22 @@
+# rst
+
+snippet :
+	:${1:field name}: ${2:field body}
+snippet *
+	*${1:Emphasis}*
+snippet **
+	**${1:Strong emphasis}**
+snippet _
+	\`${1:hyperlink-name}\`_
+	.. _\`$1\`: ${2:link-block}
+snippet =
+	${1:Title}
+	=====${2:=}
+	${3}
+snippet -
+	${1:Title}
+	-----${2:-}
+	${3}
+snippet cont:
+	.. contents::
+