Adding clang-refactor with a dummy template refactoring module.
The tool itself doesn't have to be perfect in the first iteration, so I would be really happy to push this one early enough so that everyone could start building modules on top of it. As soon as this one is landed more refactoring and cleanup patches are welcome. This also isn't about "the one true way how clang-refactor has to be designed". Thus said, consider this version of clang-refactor to be highly experimental.
Clang-refactor design doc can be found here: https://docs.google.com/document/d/1w9IkR0_Gqmd5w4CZ2t_ZDZrNLYVirQPyMS41533HQZE/edit?usp=sharing
UPD: This diff was stalled for a while, clang-refactor was introduced in https://reviews.llvm.org/D36574 patch by araphman. Removing everyone from subscribers and reviewers for convenience.