[CMake] re-config on make all

[Vandenbroucke Sander]

Hi,

Sometimes CMake re-configures my build tree when running make.
Unfortunately CMake uses wrong options, I normally set those on the
command line. This forces me to re-config & rebuild my entire source
tree. This is a bit annoying since, in most cases, this is not necessary
and takes a long time.

So here is my question: can I prevent the automatic reconfiguration and
throw an error/warning so the user can do a manual reconfig?

Sander.