FetchURLConnection to allow for the canceling of currently happening async URL connections
Merge remote-tracking branch 'origin/master'
1) Merge conflict fixes
2) When the main window loads, manually call splitView:constraintSplitPosition:ofSubviewAt: to make sure that if the url status and the text in the cells overlaps, the status is hidden
3) If a fetch is happening and you try to switch URLs, the app asks you whether you’re sure.  The fetch now cancels if you’re sure.
4) Remove unneeded, commented out code.