[CMake] Makefile build progress support

[Ken Martin]

I have added progress reporting to the makefile based builds. It is checked
into CMake CVS and "should" work with any make and parallel builds. The
percentage done is based on source file counts without knowing if the source
files are up to date or not. Specifically the progress is not a good
indicator of time left except for clean builds, it is an indicator of source
files left to consider and possibly build, if that makes any sense :)
Progress is supported for the top level all target and for all top level
cmake executable/library targets. It has had limited testing so let me know
if it fails etc.

Thanks
Ken