[Discuss-gnuradio] mblock update

[Eric Blossom]

I've merged the work-in-progress on mblocks + the usrp inband
signaling stuff into the trunk as of r5221.

The "standalone mblock" stuff is effectively done, and is usable in
its current state.  By "standalone" I mean all mblocks, no
combinations of flow graphs and mblocks.

Still remaining are:

  * finishing the host and FPGA work for inband signaling
  * gluing mblocks and flow graphs together in the same system


If you're interested in seeing what mblocks look like, there are some
examples in the QA code that show fairly typical usage (but are of
course contrived tests).

I'd suggest looking at:

  mblock/src/lib/qa_bitset.cc:
        examples of mblock composition and INTERNAL, EXTERNAL and RELAY ports.

  mblock/src/lib/qa_disconnect.cc:
        examples of reconfiguration "on the fly"

  mblock/src/lib/qa_timeouts.cc:
        examples of one-shot and periodic timeouts


The primary include files are:

  mblock/src/lib:

        mb_runtime.h
        mb_mblock.h
        mb_port.h
        mb_message.h


Eric