Add a buttonMode to grid view to enable it on pointerless devices.
Rename methods for consistency and add source code doc

to DeckView.h
Enable rotating over multiple filters, add src code doc
Do not allow that the selection moves outside in grid view.
Fix logic error in grid view
Merge pull request #583 from ZobyTwo/deck_viewer_1

Cleanup, usability fixes and source code documentation for DeckView.h and GridDeckView.h