[Cmake] depend changes in makefile generators(unix,nmake,borland)

[Bill Hoffman]

In an effort to avoid errors where make fails because depends are stale, we 
have taken
a bit of a brute force approach to fixing the problem.

If a Makefile needs to be regenerated for any reason. (a source cmakelist 
file or the cache has changed).
If you run make, the first thing it will do is cd to the top of your 
project and run make depend.

The problem is this:

DirA/Afile.cxx
DirB/Bfile.cxx  // includes Afile.h


If I change the list file in DirA, and remove Afile.[cxx|h] from the build,
DirB will have re-run make depend, or the make will fail because it will 
have a depend
to Afile.h that no longer exists.

-Bill