ENYO-2740: Fixing quirky drag/drop + IE10 Support

Prior to this pull request, there have been multiple fixes to various drag/drop events. This pull request fixes the the remaining problems seen during certain drag & drop events. This also adds the proper "text" data type during ondragstart events: e.dataTransfer.setData("text", data). This allows us to gain drag/drop support in IE10, with the help of some other changes included in this request.

Enyo-DCO-1.1-Signed-off-by: Jeremy Thomas <jeremy.thomas@lge.com>