Activate license_check.sh in Makefile, CI
Add license_check:
to Makefile, and place into do_release:
, test:
, and do_rpi2_release:
steps.
Slight modification to support/license_check.sh
, to check the state of $install_dir/LICENSE
since the license_check:
step in the Makefile is not directly dependant on the build:
step due to the omnibus call rebuilding entirely at every call.
This is the final step of 3 in answering #1518 (closed) , via shell script. Closes #1518 (closed)