tests: use NO_FORCE_HOMING with the linuxcncrsh tests

The linuxcncrsh UI has no way to wait for homing to complete, short of
polling the emcstat structure.  Rather than do that (and rather than
reimplementing these tests in python) I'm setting [TRAJ]NO_FORCE_HOMING
so that the MDI commands may run whether or not the homing has happened.

Also, remove the now-superfluous homing steps from the tests.
Merge remote-tracking branch 'origin/v2.5_branch'