grc: On Linux, respect x-terminal-emulator
Merge branch 'maint_grcwg' into master_grcwg
grc: fix port type cache for empty types
Merge branch 'maint_grcwg' into master_grcwg
utils: add error message output to grcc
qtgui: apps: with new use of the Title, the titles provided here just take up extra screen real estate.
Corrected the fast_atan2f function. Recalculated the table and corrected some errors in the code.
Error before correction: <0.111 degrees.
Error after correction: <8.20E-5 degrees
Some QA tests failed after correcting fast_atan2f function. The tests were also fixed.
blocks: UDP source does not enforce IPv4 anny more
blocks: UDP sink does not enforce IPv4
modified the qa tests to the correct values.
cleaned the code
typos and deletion of never-evaluated code

fixed a few typos in explanatory comments.
Also deleted code in
if 1:
	...
else:
	...
clauses.

Also changed a few [1.0 for i in range(...)] to in-line
[1.0] * (fft_length // 2) for superior readability.
qtgui: remove direct calls to aligned volk kernels; using dispatchers instead.

Addresses problem of using FFTW buffers on AVX machines (when FFTW is not built with AVX).

Addresses Issue #645.
Merge branch 'maint'
Merge remote-tracking branch 'mmueller/ofdm_sync_pn_beautify' into maint
Merge branch 'maint'
fix UDP test

After allowing IPv6 UDP test may fail because 'localhost' can be resolved as ::1
whereas UDP server listens on IPv4 interface. This enforces IPv4 also for client
Merge branch 'maint'
fft: fixed Nuttall window naming from nuttal to nuttall.

The old calls to nuttal are still there to preserve the API but they just point to the nuttall versions and their docs have been updated to indicate these calls are deprecated. Will be removed in 3.8.
Checking for NaN takes too much time. With some incompatibility to cmath atan2 for some NaN/Inf combinations the performance is better now.
This change should not have any impact in SDR related things. It is only for checking NaN/Inf values.