Orientation change during repo update causes error

The dialog isn't disposed of properly, so next time the UpdateService attempts to access it, it falls over. Additionally, even if it did work, the dialog is not recreated each time a progress event is received. The AppDetails deal with this, but it does so using quite a few deprecated functions, so it may be a good opportunity to clean up the code a little bit, and figure out the (new) "Right Way" to deal with orientation changes (each new Android version seems to have a new right way to do things though).