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
pmt: adding uint64 sugar
pmt: support conversion of basic pmt pairs to python
cmake and build: fixes for cross-compiling to enable ControlPort with ICE.
runtime: white space removal.
controlport: adding a 'toggle' interface for ControlPort.

This is very similar and accessed like a 'set' function only it does not take a parameter; it simply calls a function. Meant to toggle an action, like reseting the performance counters or locking/unlocking the flowgraph.
controlport: allows reset_perf_counters to be called over controlport; gr-perf-monitorx has button to call this.

Also changes the icon of the ControlPort tools to the new one.
codec2 library update
Bring codec2 up to the latest version, and add support for all six bit rates.
vocoder: add default mode parameter and updated documentation
Corrected codec2 encoder documentation.
documentation - fix example in case anyone gets confused
controlport: in gr-perf-monitorx, if all work times returned are 0, avoid a divide-by-zero fault.
docs: doxygen mangles sections named with the same reference name. ControlPort and Vocoder both used 'using' - renamed for each.
qtgui: removing unused NumberDisplayPlot; the number sink doesn't have a canvas like the other plotters do and so doesn't require this.
volk: adding a rate 1/2, K=7 convolutional decoder volk kernel.

Supports generic and SSE3. Derived from Spiral.
block interleave/deinterleave with statefull deinterleave
tests for block mode
fec: Merging fecapi with support for CC code.

Original code taken from next branch of Nick McCarthy's fecapi:
https://github.com/namccart/fecapi.git

Needs: examples, documentation, other tools.
adding ber sink to qt gui