Allow modules with the same name in app and test

[everythingfunctional]

Main programs in the app directory do not link to any code in the test directory, and vice-versa. So there should be no reason that you can't have modules with the same name in those two places. (You could probably include example in there as well. However, fpm currently complains that there are duplicate modules in this case. Also, because all of the object and module files are currently output in the same folder there is a collision of the *.mod file names.

The Haskell version was putting the outputs into different places. We should go back to doing that, and not look into app when searching for duplicate modules for test and vice-versa.