uses data() instead of attr() for fetching link params, issue rails#307

Author: phillipp

src/rails.js

@@ -186,7 +186,7 @@
       var href = rails.href(link),
         method = link.data('method'),
         target = link.attr('target'),
-        params = link.attr('params'),
+        params = link.data('params'),
         csrf_token = $('meta[name=csrf-token]').attr('content'),
         csrf_param = $('meta[name=csrf-param]').attr('content'),
         form = $('<form method="post" action="' + href + '"></form>'),