rpm packages for supporting mp3 sound forwarding with centos / fedora

[Antoine Martin]

tasks:

• new spec files
• buildbot updates
• testing

[Antoine Martin]

Spec files added in r7940.
Tested on Fedora with ./xpra/sound/gstreamer_util.py:

• before building and installing the new packages:

  encoders supported: ['wavpack', 'wav', 'flac', 'speex']
  decoders supported: ['wavpack', 'wav', 'flac', 'speex']
  

• after:

  encoders supported: ['mp3', 'wavpack', 'wav', 'flac', 'speex']
  decoders supported: ['mp3', 'wavpack', 'wav', 'flac', 'speex']
  

Tested with a win32 client which prints on stdout:

• before:

  using audio codec: Wavpack
  

• after:

  using audio codec: MPEG-1 Layer 3 (MP3)
  

[Antoine Martin]

r7988: changes needed for building on centos6+

Tested by playing a simple wav file with paplay.
CentOS can be used as client or server and support mp3 encoding.

[Antoine Martin]

I assume this works.