Large UNTESTED commit with the following changes:
* Improved DiameterIdentity handling (esp. interationalization issues), and improve efficiency of some string operations in peers, sessions, and dictionary modules (closes #7) * Cleanup in the session module to free only unreferenced sessions (#16) * Removed fd_cpu_flush_cache(), replaced by more robust alternatives. * Improved peer state machine algorithm to counter SCTP multistream race condition.