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/sh/sh.vim

@@ -41,12 +41,11 @@ endfunction
 
 function! s:ForwardToZshChecker()
     let registry = g:SyntasticRegistry.Instance()
-    if registry.checkable('zsh')
+    if registry.isCheckable('zsh')
         return registry.getCheckers('zsh', ['zsh'])[0].getLocListRaw()
     else
         return []
     endif
-
 endfunction
 
 function! s:IsShellValid()