clang-modernize: Update docs with -include/-exclude

-include/-exclude and friends have been marked as hidden options until this
point. This is no longer necessary. Update the docs to describe their effect.

Differential Revision: http://llvm-reviews.chandlerc.com/D1621



git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@190194 91177308-0d34-0410-b5e6-96231b3b80d8
clang-modernize: Tweak docs after rename

* Removing sphinx warnings about docs not in a toctree.
* Adding more links to cpp11-migrate redirect docs.



git-svn-id: https://llvm.org/svn/llvm-project/clang-tools-extra/trunk@190195 91177308-0d34-0410-b5e6-96231b3b80d8