Add CVE-2014-4971 BthPan local privilege escalation

Add CVE-2014-4971 BthPan local privilege escalation for Windows XP SP3.

This module incorporates the feedback we have gotten so far on pull request 3534 for a different module; if there is more, we will update this code accordingly as well.
I'm not sure of the purpose of the `Automatic` target here; I don't see a lot of automatic targeting going on in the module itself, but I'm kinda dumb about this. It doesn't seem like this will work at all if you're *not* WXPSP3, if I'm reading the `check()` right, so it seems like you'd want to drop this `Automatic` target.