[CMake] Patch: Add NO_CACHE option to find_xxx commands

[Miguel A. Figueroa-Villanueva]

Hello,

I would like to propose the addition of a NO_CACHE keyword to the
find_xxx commands that would treat <VAR> as a non-cached variable. I
have posted this as a feature request with an initial patch
implementing it for the find_path command. For more information look
at the feature request at:

http://public.kitware.com/Bug/view.php?id=7290

Thoughts?

--Miguel