Accept ctags development versions

autoload/tagbar.vim

@@ -934,6 +934,10 @@ endfunction
 
 " s:CheckExCtagsVersion() {{{2
 function! s:CheckExCtagsVersion(output)
+    if a:output =~ 'Exuberant Ctags Development'
+        return 1
+    endif
+
     let matchlist = matchlist(a:output, '\vExuberant Ctags (\d+)\.(\d+)')
     let major     = matchlist[1]
     let minor     = matchlist[2]