Added vim-commentary and updarted the plugins.

commentary:
Comment stuff out.  Use `gcc` to comment out a line (takes a count),
`gc` to comment out the target of a motion (for example, `gcap` to
comment out a paragraph), and `gc` in visual mode to comment out the
selection.  That's it.

sources_non_forked/syntastic/syntax_checkers/yaml/yamlxs.vim

@@ -69,7 +69,8 @@ endfunction
 
 call g:SyntasticRegistry.CreateAndRegisterChecker({
     \ 'filetype': 'yaml',
-    \ 'name': 'yamlxs' })
+    \ 'name': 'yamlxs',
+    \ 'exec': 'perl' })
 
 let &cpo = s:save_cpo
 unlet s:save_cpo