Updated README.
Update CMake build configuration.

  * Add 'CMakeUseLocalModules' for expansion of module discovery.
  * Add 'CMakeProvideUninstallTarget' to define an uninstallation target.
  * Add 'UseWintermute' to provide the necessary information for building
    Wintermute and Wintermute-related projects.
  * Add 'WintermuteDependencies' to define the requirements of building
    Wintermute.
  * Add 'WintermuteVariables' to provide variables necessary for Wintermute.