Add support for dustjs files

Check dustjs files using swiffer (https://github.com/smfoote/Swiffer.js)

syntax_checkers/dustjs/swiffer.vim

@@ -0,0 +1,38 @@
+"============================================================================
+"File:        swiffer.vim
+"Description: Dust.js syntax checker - using swiffer
+"Maintainer:  Steven Foote <smfoote at gmail dot com>
+"License:     This program is free software. It comes without any warranty,
+"             to the extent permitted by applicable law. You can redistribute
+"             it and/or modify it under the terms of the Do What The Fuck You
+"             Want To Public License, Version 2, as published by Sam Hocevar.
+"             See http://sam.zoy.org/wtfpl/COPYING for more details.
+"============================================================================
+"
+" To enable Dust syntax checking, you must set the filetype of your Dust template files to `dustjs`
+" The easiest way to do this is by installing the dustjs syntax highlighter at https://github.com/jimmyhchan/dustjs.vim
+
+if exists("g:loaded_syntastic_dust_checker")
+    finish
+endif
+
+let g:loaded_syntastic_dust_checker = 1
+
+function! SyntaxCheckers_dustjs_swiffer_IsAvailable()
+    return executable("swiffer")
+endfunction
+
+function! SyntaxCheckers_dustjs_swiffer_GetLocList()
+      let makeprg = syntastic#makeprg#build({
+                  \ 'exe': 'swiffer',
+                  \ 'args': '',
+                  \ 'subchecker': '' })
+      let errorformat = '%E%f \- Line %l\, Column %c: %m'
+      let loclist = SyntasticMake({ 'makeprg': makeprg, 'errorformat': errorformat })
+
+      return loclist
+ endfunction
+
+call SyntasticRegistry.CreateAndRegisterChecker({
+    \ 'filetype': 'dustjs',
+    \ 'name': 'swiffer'})