WHISTLE-1441: refactor to dedup some code use
KAZOO-532: if no offnet succeeds, send 503 to a-leg
KAZOO-532: formatting
KAZOO-529: Correct CSV generation when missing field
KAZOO-532: send a 686, which will map to 486 in opensips, according to karl
KAZOO-607: no need to reverse the accumulator
WIP