This allows to build BOINC on a Mac CI system as well as on a developers computer. See script headers for documentation.
The short version is:
* run ./3rdParty/buildMacDependencies.sh to compile all dependency libraries into 3rdParty/buildCache/mac (can be configured with --cache_dir)
* run ./mac_build/buildMacBOINC-CI.sh to compile all BOINC components using the build cache (--cache_dir can be used here too)
There are options for building debug versions but they are not very well tested. Currently you can't selectively build single targets using this.