enable to do commands with motions

I created to the possibilty to bind gestures and commands. You must to add a file named `commands.ini` at the root of the folder. If we run the code like this `python PyLeapMouse.py --motion`.

The code is probably not perfect, I'm not a Python developer. Please, let me know if you whant to change something. 

Motions are imprecise. Some movement are detected when there is nothing. This problem is due to leap motion. If you have a technic to be more precise, again, let me know.

This is an example of a commands.ini file.

    [screentap]

    [keytap]

    [swiperight]
    1finger: rhythmbox-client --next
    2finger: rhythmbox-client --next
    3finger: rhythmbox-client --next
    4finger: rhythmbox-client --next
    5finger: rhythmbox-client --next

    [swipeleft]
    1finger: rhythmbox-client --previous
    2finger: rhythmbox-client --previous
    3finger: rhythmbox-client --previous
    4finger: rhythmbox-client --previous
    5finger: rhythmbox-client --previous

    [clockwise]
    1finger: rhythmbox-client --play
    2finger: rhythmbox-client --play
    3finger: rhythmbox-client --play
    4finger: rhythmbox-client --play
    5finger: rhythmbox-client --play

    [counterclockwise]
    1finger: rhythmbox-client --pause
    2finger: rhythmbox-client --pause
    3finger: rhythmbox-client --pause
    4finger: rhythmbox-client --pause
    5finger: rhythmbox-client --pause