[CMake] Re-executing CMake from the Makefile.

[Óscar Fuentes]

Currently, when `make' is executed and a CMakeList.txt file is out of
date, `cmake' is automatically invoked and then `make' continues. Is it
possible to do this (on a reliable way) with an arbitrary file?

I need to re-execute `cmake' whenever certain file changes. I wonder if
is possible to do this from `make' itself, so the user does not need to
remember that he must execute `cmake' first.

-- 
Oscar