fix: make function-passing to fa-transform fields more reasonable

Previously, when a function was passed to a fa-modifier transform field
(like `fa-rotate`), `fa-modifier` expected that function to return a
full Transform array, while the most useful and expected case would be
to return the values approriate to that specific field (e.g.
for `fa-rotate="myFunc"`, `myFunc()` should reasonably return
an array [x, y, z].  Now this is the supported case.

src/scripts/directives/fa-modifier.js

@@ -114,8 +114,9 @@ angular.module('famous.angular')
               angular.forEach(_transformFields, function(field){
                 var candidate = _parsedTransforms[field] ? _parsedTransforms[field](scope) : undefined;
                 if(candidate !== undefined){
-                  if(candidate instanceof Function) transforms.push(candidate())
-                  else if(candidate instanceof Array) transforms.push(Transform[field].apply(this, candidate))
+                  //TODO:feat Support Transitionables
+                  if(candidate instanceof Function) candidate = candidate();
+                  if(candidate instanceof Array) transforms.push(Transform[field].apply(this, candidate))
                   else transforms.push(Transform[field].call(this, candidate));
                 }
               });