CMakePackageConfigHelpers: set_and_check() doesn't handle list of paths

I've a project that the export include paths, NEKO_INCLUDE_DIRS, contains multiple values. Inside *Config.cmake.in, set_and_check() is not able to handle it properly:

CMake Error at /Users/andy/Documents/workspace/neko/build/NekoConfig.cmake:20 (message):
  File or directory
  /Users/andy/Documents/workspace/neko/build;/Users/andy/Documents/workspace/neko/vm
  referenced by variable NEKO_INCLUDE_DIRS does not exist !

It would be nice to extend set_and_check()to handle list of paths as well as regular path.