Allowing the install prefixes to remain relative paths so that CPack will work on windows.  Issue 3439.
Allowing the install prefixes to remain relative paths so that CPack will work on windows.  Issue 3439.

OpenCMISS/zinc,hsorby/zinc,OpenCMISS/zinc,OpenCMISS/zinc,hsorby/zinc,hsorby/zinc,hsorby/zinc,OpenCMISS/zinc