Add async message port to switch muting on and off.
Add message port to XML file for GRC.
volk: potentially better solution to finding the architecture for ASM files.

OE bitbake environment and the SDK cross-compiling environments put the -march flag in different places. This pulls both together to search for it. Might still be a better solution out there.
volk: adding arm_neon.h headers to remaining neon proto-kernels.
uhd: fixed tagged stream block gap handling in usrp_sink
Merge branch 'maint'

Conflicts:
	gr-uhd/lib/usrp_sink_impl.cc
Merge remote-tracking branch 'argilo/mute-changes'
blocks: fix subtract_ff
blocks: fixes qa code to test more sub_XX cases.
controlport: removing use of ice for a controlport rpc.

This effectively disables the use of ControlPort for now until we build in a new middleware layer. The ControlPort API and interfaces exist but will function as nops for now.
Merge branch 'maint'

Conflicts:
	gnuradio-runtime/CMakeLists.txt
	gnuradio-runtime/lib/controlport/CMakeLists.txt
cmake: follow-up to previous merge
modtool: removing RTLD_GLOBAL hack for swig in gr-modtool.

This was removed from GNU Radio a while ago due to newer issues. Looks like it's affecting OOT modules as well.
volk: add check for posix_memalign for OSs that do not directly set _XOPEN_SOURCE or _POSIX_C_SOURCE; define and use the new variable when found.
logger: adding new configure_default_logger function to make it easier to get log file info on logger setup.
cmake: adding a function to allow components to reference submodules for display.

Mostly designed for gr-audio to print out which audio machines are enabled in the build.
audio: modified the audio registration system.

Instead of static functions and macros, this just uses simple ifdefs in the code to register new audio components if cmake found them. The code is more complicated for the developer, if we ever add a new audio machine. But this allows us to use gr-audio in statically linked cases.
volk: simplifies and fixes thread safety issue in volk_malloc/free.
Merge branch 'maint'
Merge remote-tracking branch 'arya/audio_registration'