Linux builds are still 'broken' on Travis-CI, so reverting.
Linux builds are still 'broken' on Travis-CI, so reverting.

We basically need the print support plugin in ppa:beineri/opt-qt531.

mirams/opencor,mirams/opencor,Fairly/opencor,mirams/opencor,Fairly/opencor,mirams/opencor,Fairly/opencor,mirams/opencor,Fairly/opencor,Fairly/opencor