grc: fix xterm setting check
grc: catch EOFError on fg exit
volk: adding tanh kernel with support for sse and avx.

There are two generic kernels, one using tanh and another using a series approximation. The SIMD code uses the series approximation.
pmt: Added float conversion

Added to_float() and from_float(). These are basically aliases
for *_double() with a type cast for when strict typing is necessary
(e.g. SWIG won't accept an f32 value when using from_double()).
Add vector support to abs block. Remove unused num_inputs from xml.
Fix CMake abuse for assembly (.s) files
tags_wip
Fix(?) prune_tags: needs verification
Fix prune_tags
runtime: speed up all the things
Formatting fix-ups
blocks: make tagged stream to pdu output optional
volk: add feature for json results export
digital: Removed all references to remove_item_tag()
runtime: Marked remove_item_tag as deprecated
uhd: Removed LO lock checks at startup, are unnecessary and cause bugs
blocks: added example of how to construct and add a tag to a vector_source.
docs: fixed path stripping for binary dirs in doxygen manual.
fec: turning off some debug output.
blocks: deinterleaver will process more than one block at a time for significant speed improvements.