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_f.snippet

@@ -0,0 +1,8 @@
+/**
+ * $2
+ * @return ${4:void}
+ * @author ${5:`g:snips_author`}
+ **/
+${1:public }function ${2:someFunc}(${3})
+{${6}
+}