[clang-tidy] Move some of the misc checks to readability/

Summary:
Some of the misc checks belong to readability/. I'm moving them there
without changing check names for now. As the next step, I want to register some
of these checks in the google and llvm modules with suitable settings (e.g.
BracesAroundStatementsCheck). I'm not sure if we want to create a "readability"
module, probably not.

Reviewers: djasper

Reviewed By: djasper

Subscribers: curdeius, cfe-commits

Differential Revision: http://reviews.llvm.org/D5792

git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@219786 91177308-0d34-0410-b5e6-96231b3b80d8
Reformatted code samples in the unit test. No functional changes.


git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@219788 91177308-0d34-0410-b5e6-96231b3b80d8