Allocating a pseudo-TTY (-t, --tty) fails when 'run' is executed
inside of a Jenkins or cron script. This change fixes
ttcn3-bts-test, which invokes 'run' to fetch the config files.
This change introduces a new sub-project - 'gr-gsm-master'.
It was decided to use Arch Linux as the base image, because it
provides the recent version of both UHD and GNU Radio without
tons of dependencies, such as Xorg.
Note: as there in no libosmocore package in Arch Linux, it will
be built from the latest source code.