CMake Updates, master branch (2019.01.25.)

This is a follow-up from !20525 (merged) and !20604 (merged).

While making sure that I would be able to compile packages that use tdaq-common on top of today's nightly, I found that I still forgot about updating a few things. Simply doing git grep "_ROOT}", I now tried to update all occurrences of "old style" variable usage to the new naming scheme.

On the VP1 packages I decided to do a bit more, and clean up the packages that used QT5_ROOT (for no good reason even in the past). @rbianchi, @emoyse, you guys should definitely have a look. The updates at least didn't break the build of these packages for me...

While doing this, I also found some additional issues in AthDataQuality, which I tried to now fix.