Add Autotools build system

[DWesl]

I got mildly annoyed getting my package manager to cooperate with the makefile, so I set up an autotools build system and changed the tests to support TAP. I have not run valgrind, but I do not think adding a newly generated header with a bunch of #defines would create any memory leaks.

This is one of the cases Autotools is designed for, so it was relatively straightforward. I missed a few of the names used in #ifndef clauses. Should I add those?

I might also be able to simplify the install process in Travis now. Should I try that as well?