Commit a clang-tidy config file for use with clang-tidy-3.6.

Turns off a few useful default checks just to reduce the sheer volume of
messages.
Apply all the (little) fixes that clang-tidy knows how to do.
Split out the list of "shared" code into a separate file.

Document creation of the shared list.
Sort and add a few more names to the shared list.
Update clang format a bit.