Stickies 2.1.0

* Minor fixes to issues.

* Change background util now changes image via thread so as
not to disrupt sticky editing.

* Added a global option to change sticky border style to a
rounded windows.

* Added a saving in process dialog and tray icon shows
current save state in auto saving thread.
This feature is only really noticeable when saving large
stickies (greater than 50 megs in size).