Switch to camelcase in API

Because all modern languages use camelcase and not that oldschool _ variant. Have a look onto Halion scripting, they use lua with camelcase and it looks quite beautiful and easy readable:

https://developer.steinberg.help/display/HSD/Event

Oh, btw. they use kind of API docs generator? Really nice documentation with examples :stuck_out_tongue:

EDIT: Just joking, only for some outer world inspirationā€¦