BUG: Removed ambiguity in GTM routines import directory for MUnit tests

CMake now generates a different script from RoutineImport.py.in based on
whether it is importing routines for a fresh VistA installation or importing
routines for MUnit tests.
CMake now detects the path to VistA routines directory automatically based on
the gtmroutines environment variable. This path can also be changed manually.

OSEHRA-Id: http://issues.osehra.org/browse/OAT-86
Change-Id: Ic1b68baf8dbe4670436acc25042a112e2dc64866