debug to stderr

Every log output except stream information is routed in
to the stderr.

Example usages:
Standart sysadmin approach to supress debbug output is something like this:
`sudo ./rtmpSnoop.py 2>/dev/null`
Or if people want do distinguish debbug and stream output then can do something like that:
`sudo ./rtmpSnoop.py  2> >(while read line; do echo -e "\e[01;31m$line\e[0m"; done)`