- Add combo box listing the last 10 elements of history.
- Introduce parameter class for the dialogs that can stored/
  retrieved as a QSettings array using template helpers.
- Give dialogs a static 'run()' method that returns
  the DebuggerStartParameters to handle the history, move
  code from the debugger plugin to the dialogs.

Change-Id: Ieb15f7c8ef9489f925b9d2f47ec09feebcf73826
Reviewed-by: hjk <qthjk@ovi.com>