[ofw] [RFC] plans for supporting rdma_cm on windows

[Sean Hefty]

I'm implementing the WinVerbs CM functionality.  This will support an RDMA CM
interface, including a librdmacm compatibility library.  Longer term, I may also
add a libibcm compatibility library.  I'm suggesting the following changes to
IBAL:

Export IB CM kernel interfaces separately.  The newly exported interfaces are
identical to the existing interfaces, except for a couple of minor changes.
(For example, the listen call drops the h_al parameter.)  All existing APIs are
unchanged, as is the ib_al_ifc_t structure. 

Add a new CM related object - an endpoint - which is basically a QP structure
without the hardware resources.  This minimizes internal CM code changes, which
expects an IBAL QP handle in several places.

The intent is that these changes will allow the CM to execute the CM protocol
without trying to manage hardware QP states, and provides a clean separation of
IB CM related functionality from that of a user application.

- Sean