Allow each VTK module to specify variable to export for use in either build or install tree
Each VTK modules should be able to specify variables to export, this would allow to remove the hard-coded value listed in vtkInstallCMakePackageHelpers.cmake.
Variables could be associated with only the build tree (e.g PATH variables) and some could be associated with both build and install trees.
Related issues:
Edited by Jean-Christophe Fillion-Robin