[CMake] Ignoring system paths for dependency checking

[Gregor Berginc]

> Look at the INCLUDE_REGULAR_EXPRESSION command.

I found this command few days after my post but I was unable to
prepare regular expressions that would rule out the includes from
/usr/... directories

Best,
--
Gregor Berginc, Ph.D. Student
University of Ljubljana, Faculty of CIS
Trzaska 25, SI-1001 Ljubljana, Slovenia
tel: +386 1 4776630, fax: +386 1 4264647
www: http://vicos.fri.uni-lj.si/gregor