volk: add neon kernel for 16i_convert_8i
volk: add neon kernels for 32fc->32f deinterleavers
volk: removing executable bit for volk_32f_x2_pow_32f.h
volk: add neon support for 32fc_s32fc_multiply_32fc
volk: popcnt support

Add a neon protokernel for 64-bit popcnt, and puppets so 64-bit and
32-bit versions can be tested with volk_profile
qtgui: increased max tabs from 5 to 20 in tab widget
Merge branch 'maint'
cmake: increased revision to 3.7.5.1 for maintenance release
Merge branch 'maint'
volk: adding popcnt puppets to qa
volk: add neon kernel for 16i_32fc_dot_prod_32fc
volk: add neon protokernel for 16i_s32f_convert_32f.

This is slower than the generic on gcc 4.8, but it's worth keeping
around. It's not possible to duplicate what gcc is doing with intrinsics,
but we can get close using 2 lanes.
volk: add neon version for 32f_binary_slicer_8i
volk: removed unused variable from neon binary slicer
volk: add neon version of 32u_byteswap

The QA needed a puppet because qa_utils only checks output buffers,
so this also introduces a puppet
volk: update profile to use the new 32u_byteswap puppet
volk: add neon versions for 32i bitwise operators
blocks: adding a tanh lut for control_loop blocks to use.
digital: adding use of tanh and snr info to costas loop.
volk: fixing 32u_byteswap puppet for SSE