pass *args and **kwargs through mappers

[dham]

Cause mappers to pass through additional arguments more consistently. This facilitates the subclassing of mappers. For example, one can implement a subclass of stringify which automatically indents code. This requires the current indentation level to be passed through the mapper.

[inducer]

Thanks! :)

[inducer]

Btw, do you need this in a release sometime soon?

[dham]

It's not mega-urgent. I'm happy tracking master. We might still come up with more changes in the course of doing FInAT