Rewrite CMake configuration in "modern CMake"
Rewrite of the CMake configuration along the lines of LHCb!2931 (merged) (see there for more details).
Requires Lbcom!551 (merged), LHCb!2931 (merged) and Rec!2416 (merged)
It also requires that lhcb-core/LbDevTools!176 (merged) is deployed and used in the nightlies to be able to test.
Edited by Marco Clemencic