osm2pgrouting 2.0.0: Install with 'make install'

Patched the CMakeLists.txt file so that install paths are relative to
the cmake prefix (which is specified upon invocation of cmake).

This allows installing everything with 'make install'.
osm2pgrouting 2.0.0: Removed formula test

The test didn't actually test for anything useful.
Currenty, the program needs a valid DB connection and two input files in
order to return a success code, so no way to test it.