Other ninja fixes
Thanks for fixing the ninja build @JordyAaldering ! These are the other fixes I made to have it work for me, feel free to do with it what you want!
This should (?) fix the FUNCTESTS on ninja.
For the commit which removes the + before CMAKE_COMMAND, I'm unsure if that will break other people's setup when using Make or not. I wasn't able to find a reason why that is there, but it doesn't play nice with ninja for me.