Added enum for difficulties
Added DownloaderFragment
Handles requests and downloads of bugs.
Added callback methods for several fragments
Updated python name
Editor now saves bugs
Bugpicker fragment now establishes server communication
Buglist now resumes bug correctly
BugDataSource can now update bugs
BDS now handles solution id in addition to bug id
Bug now has solution id
Placeholder xml for downloader fragment
Merge remote-tracking branch 'origin/master'