CLT: rename Mavericks CLT path constant.
Xcode: don't detect Mavericks CLT as Xcode.
CLT: correctly find Mavericks CLT PKG.

Closes #23445.
brew-pull: fix whitespace handling.
mysql: rename the test() macro to mysql_test().

This seems to be enough to make it compile on 10.9.

Closes #23131.

Signed-off-by: Mike McQuaid <mike@mikemcquaid.com>