I removed icy- support from the generic send headers function, as it is my
understanding that only MP3 sources use icy headers. PLEASE correct me
if I am wrong.

I also added code in the mp3 function to convert ice-audio-info bitrate to
an icy-br header. ice-audio-info is for YP, icy-br for clients. Perhaps we
should send both to clients though?

svn path=/trunk/icecast/; revision=5079