Added destroyfailed event

Added possibility to inform user about failed deletes.

to be used with:
$('#fileupload').on('fileuploaddestroyfailed', function (e, data) {/* ... */})
Merge pull request #2859 from jbirkholz/master

Added destroyfailed event
Updated version number.
Don't throw errors when file path  given to exif_imagetype is empty.
always clear fileUploadPreview directive element on preview change
Merge pull request #2889 from danxshap/angular_clear_preview

Always clear fileUploadPreview directive element on preview change
Updated version number.
Only enable the start button if the processing succeeded. Closes #2894
Bugfix release.
Allow chunked uploads together with max_number_of_files setting. Closes #2899
Updated jQuery UI Widget Factory and fixed AngularJS widget options handling. Closes #2904
Allow client-side previews of SVG images. Closes #2912
Handle processing promise callbacks independently from transition callback. Closes #2933
Bugfix release.
Fixed IE8 + angular issue which causes a stack overflow. Fixes #2940
Merge pull request #2941 from rikkertkoppes/master

Fixed IE8 + angular issue which causes a stack overflow. Fixes #2940
Refactored last merge to fix HTML5 data-attributes handling.
Prevent orienting the same image twice. Fixes #2599
Updated referenced jQuery version.
Updated referenced QUnit version.