Fix for issue:
Reading file contents is not compatible with IE for mobileweb
https://jira.appcelerator.org/browse/TC-2628
Fixed issue where mime type of "application/json" was seen as binary.
Merge remote-tracking branch 'upstream/master'
Merge pull request #4460 from brentonhouse/master

[TIMOB-14611] Reading file contents is not compatible with IE for mobileweb