Dolphin[Qt|WX]: Miscellaneous cleanup.

DolphinQt:
 * Make the connect() calls explicit, not automatic
 * Follow better naming convention for the QActions
 * Remove the Open action from the toolbar.

Dolphin[Qt|WX]:
 * Move the "Skip Bundle" option to the root CMakeLists so that both DolphinQt and DolphinWX can use it.