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/ruby/tc.snippet

@@ -0,0 +1,9 @@
+require "test/unit"
+
+require "${1:library_file_name}"
+
+class Test${2:`Snippet_RubyClassNameFromFilename()`} < Test::Unit::TestCase
+	def test_${3:case_name}
+		${4}
+	end
+end