Add :parse_ts option

Allow disabling of timestamp parsing from rails logs we might have a log
filter which does a better job.
Add ruby log formatter filter
Remove parse_ts option
Capture message when we parse out the timestamp
Added tests for ruby_log_formatter
Added ruby_log_formatter files to gemspec
Don't fuck up the TZ env var for other tests
Don't skip out the timestamp heuristic if we're given an accurate timestamp
Updated gemfile.lock
Tidy up the timezone handling and tests a little
Use the ruby-log prefix as a captured-at value
Make the gemspec executable to build the gem
Make the regexp more forgiving
First stab at a rails multiline message filter that respects the request id and pid
Working, but ran out of timers, try and coalesce them
Adds a pid demuxer, to extract out that complication
Handle the tidy-up of unused PID objects
Allow nil sinks
Attach newline'd log-entries onto the previous pid output
Working rails request filter