Fix android string conversion of FB.ui result
Fix native interface for FB.ui

The facebook javascript interface FB.ui with method `apprequests` now
matches native for closing with sending, closing without sending, and
ending the dialog via the "x" button. This was accomplished partially
through javascript response transformations.

There is a base ResponseTransform class which defines an interface for
transforming result data. There is an implementation for both iOS and
Android which handle all presently known FB javascript SDK interface
discrepencies.

Mocha tests were added to ensure we don't have regression in the
complicated result transformations. travis-ci was intergrated to make
sure patches submitted by others have the tests run when pushed.