Update inline documentation
Remove (comment) old GoClear code, not implemented
Enhance log and error counters and handling of messages

ZRTP and SDES have own counters for protect and unprotect RTP/SRTP data and moved
these counters to the public area of the class.

Prepend each the info/warning/error string with a unique identification that
mirrors the sevrity and message code in ZrtpCodes.h. Applications may use this
id code to identify messages in an easy way. The id code conforms to Android's
XML naming restrictions.

replace the fixed ZRTP sequence number start with randomized data.
Fix threshold counting
Add global logging functions pointer, fix statistic counter
Fix small typo in comment
Fix and enhance inline documentation
Fix initialization of conf2Ack simulation event