Log Message:
libgroove: Upgrade to 4.3.0

pkgsrc changes:
 - reuse the github framework
 - disable -Werror
 - set -D_NETBSD_SOURCE for NetBSD, this is required for obtaining
   pthread_condattr_setclock(3) and pthread_condattr_getclock(3) on NetBSD
   compiled on version <8.0 (bug in a header)
 - switch from ffmpeg2 to ffmpeg3
 - add a workaround for a detector of ffmpeg in a homegrown dependency
   detector, this hardcodes paths to headers and libraries of ffmpeg3

upstream changelog
==================

Version 4.3.0 (2015-05-25)

    player: Add support for "exact mode" - re-opens the audio device \ 
when a buffer is encountered that does not match the open audio device's sound \ 
parameters.
    build: Simplify cmake find modules.
    Add const qualifier to some fields and functions.
    metadata example: print the number of channels.
    Add documentation.
    Add more channel layouts.
    build: Compile in Debug mode by default.

Version 4.2.1 (2014-10-07)

    updating metadata: set time_base on stream not the codec
    libav lockmgr: set mutex pointer to NULL on destroy
    fix build on GNU/hurd

Version 4.2.0 (2014-09-25)

    build: remove bundled dependencies
    build: simpler cmake find modules, both code and license
    player: add shim to fix build failure on OSX

Version 4.1.1 (2014-06-20)

    playlist: fix race condition which can cause decoder to hang
    dummy player: fix timing issues

Version 4.1.0 (2014-06-13)

    playlist: added groove_playlist_set_fill_mode. Allows you to choose between \ 
buffering until all sinks are full and buffering until any sinks are full.

Version 4.0.4 (2014-06-03)

    Fixed a race condition where seeking to a different playlist item and then \ 
back would have a window of time where it could report the wrong position.
    Properly play and pause network streams.

Version 4.0.3 (2014-05-31)

    build: update bundled libav to latest stable 10 release
    build: link player with -lrt for clock_gettime. closes #67
    playlist: fix case where filter graph was not being rebuilt. closes #65
    playlist: fix race condition segfault when attaching a sink
    encoder: properly reset encoding when flush or playlist end is encountered. \ 
closes #66

Version 4.0.2 (2014-05-20)

    player: thread cleanup only if thread was initialized - fixes potential \ 
crash on player detach
    build: look for includes in the current source tree. Fixes an issue when a \ 
previous version of the library is installed.
    build: on unix link with -lm

Version 4.0.1 (2014-05-13)

    groove_playlist_get_position: always set seconds even when item is NULL
    playlist: correct generation of the sink map
        fixes potential error when adding multiple sinks
        optimizes some cases where sinks can share filter graph chain
        dummy player now uses disable_resample optimization
    dummy player: avoid floating point error accumulation

Version 4.0.0 (2014-05-12)

    GrooveBuffer struct contains the presentation time stamp
    move include statements to outside of extern C
    ability to set true peak on playlist items. closes #50
    support per-sink gain adjustment. closes #41
    GroovePlaylist: volume renamed to gain
        groove_playlist_set_gain renamed to groove_playlist_set_item_gain
        groove_playlist_set_volume renamed to groove_playlist_set_gain
    player: specify device by index rather than name. closes #44
    player: ability to attach a dummy player device. closes #60
    fingerprinter: encode/decode return 0 on success, < 0 on error
    fingerprinter: info struct contains raw fingerprint instead of compressed \ 
string. closes #61