Remove various 32-bit assumptions scattered throughout the codebase.
The code is still not necessarily 64-bit clean, but will at least
compile.

This brings us in to line with Linux definitions, and also simplifies
adding x86_64 support since both platforms have 2-byte shorts, 4-byte
ints and 8-byte long longs.

These cards very nearly support our current IB Verbs model.  There is
one minor difference: multicast packets will always be delivered by
the hardware to QP0, so the driver has to redirect them to the
appropriate QP.  This means that QP owners may see receive completions
for buffers that they never posted.  Nothing in our current codebase
will break because of this.