Initial preferences window implementation.  General settings tab in progress
Preferences dialog, a few persistent settings now implemented.  Able to display tabs vertically, lock tab position, hide the tab bar, change highlight style... Maybe more
Change a line to use QApplication palette.
Merge pull request #27 from Teklad/prefs

Preferences Dialog initial implementation.... a few settings are usable.
Merge pull request #6 from notepadqq/master

merge changes from upstream