Changes

osmo-gsm-tester: Use non 'inst' name as target install dir, and remove
it once archived
osmo-gsm-tester uses also the "inst/" directory, so using that name to 
install from cmake is not a good idea here, since they will end up in 
the same directory under /tmp/trial/inst. Also, make sure the temporary
install dst directory is removed after creating the archive, since at
that point is no longer needed.
Change-Id: Ib6610487140f0703d5817241bc4a63027696c1d4

osmo-gsm-tester: Allow changing host's trial directory
It's set to /tmp/trial by default for convenience, since it's a 
temporary directory and easy to remember and to access. Still, let's 
give the opportunity to change it (if user wants it to be stored in 
persistent data or if has low amounts of non-persistent memory).
Change-Id: I2a7ea361c6156c97bd8d2d94cf1b6856344d4d9f

osmo-gsm-tester: Print colored run output succes/failure
This way one can quickly see if osmo-gsm-tester run fine or an issue 
ocurred and logs need to be checked.
Change-Id: I0b267889f403fc1505f9dd859568bc15a120dd81