Corosync module for Asterisk

Corosync is an open source group messaging system typically used in clusters, cloud computing, and other high availability environments. Using Corosync together with res_corosync allows events to be shared amongst a local cluster of Asterisk servers. Specifically, the types of events that may be shared include: * Device state * Message Waiting Indication, or MWI (to allow voicemail to live on a server that is different from where the phones are registered)