This patch is to have clang++ (>= 3.2) happily build OwlPS Positioner.
For some reason it doesn't work on NetBSD, but it is fine on GNU/Linux
and (a couple of warnings apart) on DragonFly BSD.
To be consistent with the other modules, the positioning server must be
called OwlPS Positioner instead of Positioning, and the executable
owlps-positionerd (even if the daemon mode is not implemented yet).
That's a big commit for a tiny change.