Added some test files, to be run with nosetests. Various small cleanups in
core files.
Test files for info and tactics, deleted some outdated files and information (more to delete).

Cleanup of info and goals files.
Tiny optimization: if a goal is of the form Sub(a, a) (compared by pointer equality), then the goal is not added to the list
of TCCs. This dramatically reduces the size of generated TCCs. Small performance boost.
Small bug-fixes, cleanup in terms.