Merge pull request #476 from goerz/ctags_options

Add g:tagbar_ctags_options

autoload/tagbar.vim

@@ -1092,7 +1092,14 @@ function! s:ExecuteCtagsOnFile(fname, realfname, typeinfo) abort
         "intended to be in an argument, spaces in a single ctag_args
         "string would be ambiguous. Is the space an argument separator
         "or to be included in the argument
-        let ctags_args  = [ '-f',
+        let ctags_args = []
+        if exists('g:tagbar_ctags_options')
+            for value in g:tagbar_ctags_options
+                call add(ctags_args, '--options='.value)
+            endfor
+        fi
+        let ctags_args  = ctags_args + [
+                          \ '-f',
                           \ '-',
                           \ '--format=2',
                           \ '--excmd=pattern',