Make it possible to alter behavior of the standard make targets

[seth]

Ideally, users would be able to customize the behavior of the targets in an elisp advice sort of fashion: you should be able to specify targets that run just before a standard target, just after, or be able to replace/overwrite a standard target entirely.

It might be worth looking at the other Make-based erlang project from the cowboy folks as they may have solved this in a nice Makey way. But it also might be as simple as:

test_BEFORE test_AFTER