Allow to use FairRoot from a Spack installation
Remove check for ZeroMQ. ZeroMQ isn't needed any longer.
Fix installation of externals when using Spack. Pass extra flags flags to NicaFemto configuration if needed. Patch ipc source code. Add missing include file. Cleanup .gitignore in externals.
Fix linking of CbmGlobalTraking library. Add missing link directory. In normal installation Vc probably was found in the ROOT installation. With Spack ROOT is build without builtin Vc.
Use correct syntax for function call. With the latest FairMQ version the old backward compatibility layer was removed. Use now the new syntax to change the state.