- Removed all INCLUDE_DIRECTORIES commands from subdirectories of
   build tree other than Utilities, Examples, and CMake directories.
 - Added vtkIncludeDirectories.cmake to construct an ordered
   list of include directories.  One INCLUDE_DIRECTORIES command
   now adds all of them at once.  This will solve problems
   with system include directory ordering.
 - Renamed GenerateVTKConfig.cmake to vtkGenerateVTKConfig.cmake for
   consistency.
 - Removed vtkCMakeOptions.cmake.  It is no longer needed with new UseVTK.
 - Created vtkLoadCMakeExtensions.cmake module to define
   VTK_LOAD_CMAKE_EXTENSIONS macro.  This will compile/load the
   VTK-specific CMake commands.
 - Added CMAKE_EXPORT_BUILD_SETTINGS to store VTK's compiler settings.
   UseVTK.cmake now uses CMAKE_IMPORT_BUILD_SETTINGS to load the settings
   into a user project.