* Organize argparser help text
* NEW parameters for `glitch_image` and `glitch_gif` in `glitch_this.py`:-
* `glitch_change`: Increment/Decrement `glitch_amount` by given amount after every glitching
* `cycle`: Whether or not to cycle `glitch_amount` back to 1 or 10, if it overflows or underflows
* `step`: Glitch every step'th frame, instead of all of them
* NEW parameters for `commandline.py`:-
* `-i, --increment`: Increment/Decrement `glitch_amount` by given amount after every glitching
* `-cy, --cycle`: Whether or not to cycle `glitch_amount` back to 1 or 10, if it overflows or underflows
* `step`: Glitch every step'th frame, instead of all of them
* `relative_duration`: Use a duration relative to the source GIFs duration