cp11-migrate: Integration with LibFormat

Adding a feature to optionally reformat code changed by the migrator. Like
LibFormat, can choose between built-in styles (LLVM, Mozilla, Google, Chromium)
or use a YAML-format config file.

Author: Guillaume Papin <guillaume.papin@epitech.eu>



git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@186866 91177308-0d34-0410-b5e6-96231b3b80d8