[CMake] MESSAGE SEND_ERROR and FATAL_ERROR

[Bill Hoffman]

I want to change SEND_ERROR to do a FATAL_ERROR in the MESSAGE command.
This it to make the required modules stop processing the cmakelist files
at the first SEND_ERROR.   Currently it works like this:

SEND_ERROR: prevents the generate step from happening, but cmake continues
to process files during the configure step.

FATAL_ERROR: cmake sends a message and immediately stops the configure step
and does not process any more files.


I want them both to stop cmake processing.

-Bill