Added getFilesFromResponse option method

This new overridable option method allows server responses to be
refactored into a compatible files array.
Remove the temporay upload form in a setTimeout call. Closes #2267.

Fixed JSLint validity.
Prevent reporting 200% progress for chunked uploads on Firefox - Closes #2269.
Merge pull request #2270 from david-hollifield/master

Added a new getFilesFromResponse option method
Refactored last merge and updated version number.
Use getFilesFromResponse from options if not available as data property. Fixes #2273.