analog: white-space fixes
analog: disable deemph for tau=0.0 in fm_demod
Add a lookup table to the encoder inner loop for byte mode only
(used by the ATSC transmitter).
doxygen: fixed documented include paths

* Docs say #include <gnuradio/blocks/add_ff.h> instead of <add_ff.h>, etc
Windows compatibility fixes

* cmake: use CMake's internal variables for compiler info
* volk: void* can't be used for pointer arithmetic in MSVC, so cast
wxgui: fix bug where grc_gnuradio files aren't added to NSIS installers
docs: fixes issues with building docs when various components are not enabled.
digital: fixed differential handling for dpsk mod/demod blocks. Also fixed docs.
Merge remote-tracking branch 'skoslowski/analog_fm_deemph_fix' into maint
fix gr-audio osx:
+ use GNU Radio preferences file to set default input and output audio device, if provided;
+ use gr::logger for all non-debug messages;
+ case-insensitive string find with desired audio device name;
+ fixes buffer allocation bug with low sample rates;
+ allows using a specific (named) audio device, or the default;
+ handles the case when the selected audio device becomes unavailable (e.g., a USB stick is removed while in use);
+ if no audio device name is provided, uses the default audio device as found in System Preferences::Sound;
+ handles the case when the default audio device is in use, and the user changes that audio device in System Preferences::Sound, by internally resetting to use the newly selected audio device;
+ all non-Apple names are now lower_case, not CamelCase;
+ move osx_impl functions to gr::audio::osx, and use them correctly;
+ install osx_impl.h to expose gr::audio::osx functions, but iff OSX audio is enabled.
Merge branch 'maint'
Merge remote-tracking branch 'drmpeg/rs-optimize'
fec: adding small comments in rs encoder about duplicated lines.
vocoder: Fixed packing problem with Codec2, + GRC bindings, added example
vocoder: Fixed GSM GRC bindings and improved docs, provided example
runtime: adds ability to output flowgraph in dot format (resolves issue 245).
Merge remote-tracking branch 'mbant/vocoder-fixes'
vocoder: cleaned up documentation (removed warning on trademark symbol)
Merge branch 'master' into next
Merge remote-tracking branch 'ncorgan/wxgui_win32_cpack' into maint