r4019: Add support for userspace RDMA connection management abstraction (CMA).

r4019: Add support for userspace RDMA connection management abstraction (CMA).

- Adds common user/kernel data structures and copy routines in ib_uverbs and
  libibverbs.
- Update ib_ucm and libibcm to use common structures and copy routines.
- Add new kernel module, rdma_ucm, to support userspace CMA.
- Add userspace CMA library, librdmacm.
- Add userspace CMA test program.
- Update kernel CMA to support userspace CMA library.
	- Add support for users to transition QP states.
	- Add backlog parameter to rdma_listen API.

Signed-off-by: Sean Hefty <sean.hefty@intel.com>