Tests

* Ported @cwalther's tests over
* Changed CMake for 1 test app per library project
* Added `make check` to build and run all tests

I think the pfPython tests will probably fail to link unless we dump the all the projects in as target_link_libraries (at least, until H-uru/Plasma#383 is fixed) :(

I know I'm fiddling with a bunch of stuff, so let me know if there's anything you disagree with.