pmt_io: adding string conversion for uniform vectors

Sadly, this needed expansion of unv_template, otherwise I'd have to
hand-write gengen-style code in pmt_io.cc
Initial import of gr-zmqblocks OOT project as-is, prior to rework for in-tree
zeromq: initial surgery to add to master build
zeromq: Initial conversion of include/gnuradio/zeromq files
zeromq: first cut at compiling lib/ directory
zeromq: cleanup and reformatting
zeromq: converted SWIG to in-tree build
zeromq: first try at enabling Python.  Segfaults in SWIG code.
Fix ZeroMQ cmake module.
Fix callback function to work with multiple arguments and return None
in case of error.
zeromq: Fix typo in CMakeLists to link against libzmq
zeromq: Rename "zmqblocks" to zeromq in examples
zeromq: fix import in example
zeromq: renamed sink_pushpull push_sink
zeromq: renamed source_pushpull to pull_source
zeromq: renamed sink_pubsub to pub_sink
zeromq: removed feedback source
runtime: fix propagation of DONE state to message blocks
audio: osx audio fixes

- fix dequeue to return 3 when the requested number of items to dequeue is not the same as the actual number of items. fix comments to reflect this change as well as the actual input and output info for this variable.

- fix comments. fix debug printouts to be consistent.

- fix the AU callback to not throw, since it is not handled robustly by the OS routines that to the call.  Add NOTE to this effect.  Return better error codes when an issue arises.

- correctly convert d_buffer_sample_count to int before using it.

- when stopping: if waiting in ::work, signal the thread to wake up, in the hopes that it will correctly return and terminate.  After stopping the AU, abort and reset buffers as well as clear our local knowledge about the amount of data in the queues.
whitespace only