Merge branch 'master' into safe_align
Conflicts: gnuradio-core/src/lib/filter/gr_fft_filter_ccc.cc gnuradio-core/src/lib/filter/gr_fft_filter_fff.cc
core: expose nthreads setting through to fft_filters.
Can set nthreads as last arg to filter; defaults to 1 so no change in default behavior.
core: redo fft_filter (complex and float) with Volk.
No need for sse implementation now but keeping code for reference.
math explicit type overloads:
Use explicit data type casts in math functions where the overloaded function could not be determined.
Added missing header includes for memcpy
Removing SSE version of FFT filter until we work out how we want to handle the SSE the use of intrinics. Code for the SSE versions is still there just disabled.
Adding SSE version of fft filters. Complex (ccc) version working.