Add InstallArea directories to CMAKE_PREFIX_PATH
This allows to build plain CMake projects (not Gaudi-like) in a slot and have CMake find them without custom hacks in the configuration, like LHCbNightlyConf!355 (diffs)
This allows to build plain CMake projects (not Gaudi-like) in a slot and have CMake find them without custom hacks in the configuration, like LHCbNightlyConf!355 (diffs)