Monal OSX has inline images

I had a few spare minutes today, so I decided to finish support for inline images in chat in the OS X client. Most of this will come to the iOS client as well. It does not yet support the privacy setting to disable checking the HTTP head of every link to identify an image  but beyond that it is mostly done.  I also added support to OS X’s quick look as well as markup for images that can now be dragged into the text field before uploading. screen-shot-2016-09-17-at-11-24-14-pm screen-shot-2016-09-17-at-11-23-57-pm screen-shot-2016-09-17-at-11-13-02-pm