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/php/doc_h.snippet

@@ -0,0 +1,10 @@
+/**
+ * ${1}
+ *
+ * @author ${2:`g:snips_author`}
+ * @version ${3:$Id$}
+ * @copyright ${4:$2}, `strftime('%d %B, %Y')`
+ * @package ${5:default}
+ **/
+/**
+ * Define DocBlock *//