Binary artifact output directory
Created by: dominikwerder
Description of work
Some changes in the past caused build artifacts to be placed in different locations depending on Release or Debug.
Since cmake can not handle unrelated build modes in the same build directory anyway, it's been decided to unify the location of the resulting binaries.
Executables are placed in ./bin/ like it has been the case previously for the Release build.
This also instructs make to run 4 jobs in parallel, reducing time on Jenkins from 12 min to 7 min during the last test.