[NTG-context] New module: simplesteps.

Well.... since Raw Steps did not work with mkiv, I tried making a very very simple module for a "beamer-like" behaviour. I don't really know how to write a module... but here is what I did: https://bitbucket.org/andrecaldas/math-video-classes/src/9116599821fc246cb54... I use \startbuffer and \stopbuffer, and also Lua. As I said, I don't really know how to write a module... comments are very welcome. Is it ok if I send a PDF sample to the list? Cheers, André Caldas.