Fix #60: W32FileMonitor. - #100

I can see how this would affect the 32-bit version. In addition, I think all of the _PTR variants should add a .toPointer() method, which further makes clear that their value can be either integer or pointer. rkey.getValue().toPointer() would make this particular expression more clear, and avoid new Pointer(), which implies something different.

I added toPointer to ULONG_PTR, which does make this much cleaner.

This affects both the 32 and the 64 bit versions. The problem is that the map has HANDLE and the result of GetQueuedCompletionStatus is a ULONG_PTR. So you cannot lookup one by the other. We could add a way to compare a HANDLE to a Pointer transparently, but that's something that seems like an overkill and a possible source of confusion elsewhere.