[clang-tidy] Python script for easy check rename

Summary:
Script can rename check that is in same module - I found it useful.

Diff generated in root directory of clang-tools-extra project.

Reviewers: sbenza, aaron.ballman, alexfh

Subscribers: mgehre, xazax.hun, cfe-commits

Differential Revision: http://reviews.llvm.org/D13440

llvm-svn: 249970