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_i.snippet

@@ -0,0 +1,8 @@
+/**
+ * $1
+ * @package ${2:default}
+ * @author ${3:`g:snips_author`}
+ **/
+interface ${1:someClass}
+{${4}
+} // END interface $1"