* Merge
* Clean up
* More clean up
* Ensure image import works when type is not set, clean up post import actions
* Removed spurious new line
* For non image files insert a tiddler link
* Added documentation for new settings and features
These changes allow drag and drop to work with one issue: <a> links are
not draggable; draggable divs, spans, buttons etc. seem to work fine.
There’s some issue with IE11 that I don’t understand.
For testing, you can force links to become spans by changing line 64 of
$:/core/modules/widgets/link.js to:
var domNode = this.document.createElement("span");
