initial work on drag and drop
created a widget for the drag and drop zone
remove debug code
drop overlay shows up when when dragging over actual InsertMedia modal now
cleanup some development code
VE-114 comment code and methods
VE-114 cleanup from code review
VE-114 remove initialize method
VE-114 add styles and copy for new drop target
remove api temp upload
Merge branch 've-sprint-8' into VE-114
VE-114 move file change event to parent view, address CR comments
VE-114 create setup and teardown methods for DropTarget
VE-114 update i18n message
address CR comments @inez
Merge pull request #2296 from Wikia/VE-114

VE-114 Dargon Drop