Added support for oblique gesture swipes.

[oryasida]

To add the support the config class was modified to include the new gestures types: left_up, right_up, left_down, right_down. Also changed the way the commands are saved in the config class, so there won't be a need for a lot of if statements to handle 4 finger swipes and 3 finger swipes. Finally, the handle_swipe_event_without_coords was modified to detect the oblique swipes. Addresses issue #2

[Coffee2CodeNL]

Looks great!

Thank you so much 😁👌

[vredesbyyrd]

Thank you! Giving these changes a test drive and everything works great :) Your guys work is very appreciated. With libinput-gestures there was often a small but perceivable delay with certain commands / gestures. I am not seeing that with gebaar. Right on 👍