another checkpoint... chan_zap can now use the new ZT_ECHOCAN_PARAMS ioctl if it is present, but doesn't parse any supplied parameters yet

(this implementation is not very memory efficient as the parameters and their values will be duplicated for each channel that has the same settings, but we can worry about that later once it is working)


git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@96019 65c4cc65-6c06-0410-ace0-fbb531ad65f3