py5 compatibility mode

[villares]

As Processing Python mode is lagging behind in maintenance, and py5 is going forward and getting nicer and nicer, I had a change of heart about using new snake_case names for everything (something that bothered me very much before in p5py the other, pure Python, project to recreate Processing with Python).

Now I kind of got used to it. One thing that made a difference for me is that py5's API and documentation is so complete, it maps well with the underlying Processing API, so beginners can do almost everything Processing Java can do, and have good support learning it.

So.... I think I'd like to have the new py5 names in pyp5js now 😄