General cleanup:
- Remove artifacts of lock yielding. This includes cursor yield and temp
  lock release code (tests were fixed/renamed as a result)
- Lots of #include fix-up after deleting db.h, which was only used for
  dbtemprelease, which is now gone. Prefer qualified include paths.
- Change header guards to #pragma once in storage/* files to be more
  consistent with the rest of the code base.
- Remove visual studio auto generated files. They shouldn't be in
  github.