Do not use get_filename_component to determine VTK_INSTALL_PREFIX
This issue was created automatically from an original Mantis Issue. Further discussion may take place here.
On systems with /lib64 -> /usr/lib64 (Fedora UsrMove), VTKConfig.cmake incorrectly set VTK_INSTALL_PREFIX to "/", resulting in "//include/vtk" in VTK_INCLUDE_DIRS. VTK_INSTALL_PREFIX is known at compile/install time and should be set accordingly.