Bump to R16B01
Merge branch 'v69' into v69-R16B01
Update invalid log message for rfc5424

The HTTP API used to not accept the STRUCTURED-DATA field of logplex
messages, but this is no longer true as of May 2013. The documentation
(last edited before then) didn't reflect the change.
Move web responses before IO logging calls

With IO being blocking for individual processes due to Erlang's IO
protocol and logplex using io:format/2 to log information, it is
possible that a node that does a lot of logging has bad tail latencies
on its API as reported by issues #49 and #51 on github.

This quickfix, pending a rewrite of the logging system to be
non-blocking and load-shedding, moves the logging outside of the
critical path for part of the requests as a whole. Some requests, such
as token creation for channels (POST /v2/channels/(\\d+)/tokens) still
contain logs in said critical path and will only see minor improvements.
Live upgrade procedure v69 -> v69.1
Support more transition versions

R16B01 and R16B01-swfi are forks of v69 that were supported for
a while and need to be able to upgrade too.