FLUID-5168, FLUID-5167

input to the files and dependencies properties in a json dependency file can take the form of an array, comma separated string, or not be present at all. These are normalized internally to arrays. 

Also file paths specified are all relative to the json dependency file, instead of the grunt file.

http://issues.fluidproject.org/browse/FLUID-5167
http://issues.fluidproject.org/browse/FLUID-5168