Add support for Files Array Format in packageSpecific.files to Allow for Additional Single Package Flexibility

[kyledmoore]

See my comment in issue 58

Within a single packageSpecific block, it'd be nice to be able to send resources of a single type to multiple destinations (i.e., fonts_dest, and images_dest are great, but don't encompass all potential use cases) and with differing options (e.g. keepExpandedHierarchy:true for some assets, false for others).