Added client_credentials support.
Added bing tts support.
Added tts service token cache for bing.
Added xunfie tts port driver.
Added google tts and xunfei tts support.
- Use binary other than list representation.
- use 3/4 fileno other than STDIN/STDOUT, because libmsc.so used STDOUT
for debug.
Added broadcast iteration support.
Merge branch 'stable' of ssh://kazoo/opt/kazoo into stable