re #4358 : lager_tcp_backend uses a configurable module to format trace log statements and communicate with listening server over tcp
formatter must supply full binary to send on the wire
use an explicit utrace severity to avoid performance issues in the console backend - debug logs will be skipped right away
Fix get_loglevel on tcp backend to meet lager's API and return a level number
Merge branch 'develop'

Conflicts:
	src/lager_tcp_backend.erl