Save settings less aggressively.

Remove saving settings on auto-save, and only save settings when
switching away from projects mode, instead of any mode switch.

Change-Id: I3369b7f5ee785467d57c47e1a194a8ef989b98fb
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>
EditorManager: Add OpenEditorFlags to openEditorWithContents

This requires moving the activateEditor call into openEditorWithContents.

Remove that line elsewhere when editors are constructed. Keep it when
reusing an existing editor though.

Change-Id: I872f03e16fde42f3b8adec2cf2344b7cc495cd08
Reviewed-by: Eike Ziller <eike.ziller@digia.com>