Key shortcut for File->Save

[Stephen Gatesy]

Could a simple Command+s or Control+s be added to let users save frequently without having to use the menu dropdown? I save about 10-20 times more frequently than quitting, yet Quit has a shortcut. Is there a reason why saving does not?

[Elizabeth Brainerd]

Yes, the standard keyboard shortcuts command-S (save) and command-A (select all) do not work in Mac OS.

[Benjamin Knorlein]

fixes #52 Added shortcuts for save, new, open and close dataset and added CTRL-A shortcut. Also added a confirmationdialog for saving.

→ <<cset a2d66d43c7bd>>