Need to prevent direct images pasting using Safari

[cyrilbornet]

Safari (at least on Mac) allows user to copy-paste images directly in the text by rendering them in the form of

Needless to say, the image is not uploaded and disappears as soon as the page is refreshed.

A quick&dirty fix for this could be to update the paste plug-in of the common package, at lines 246-248:

restoreSelection(range);
if (content.indexOf("webkit-fake-url://") != -1) return;
prepRangeForPaste(range);

Works seamlessly on dhwriter.
Credits for this idea to jejacks0n/mercury#179