Handy utility functions and unit tests

There are several functions that I've found myself re-writing that seem like they'd be good candidates for including in Nife_Util, so I added them.

I've also added some unit tests.

I tried to order my commits most-to-least invasive, additions-to-your-project-wise, so if you don't like the Makefile or the unit test but you do like the new functions, you could just merge the earlier ones.

I'd love a new tag from all this!