Use new node-txstatsd package for statsd logging

Our custom statsd logger didn't actually work properly. I didn't feel like
debugging it, so I extracted https://github.com/wikimedia/node-txstatsd from
OCG (which works) and plugged it into restbase. Along the way I also cleared
up the metric names slightly, and fixed a name clashs between the option
method & the internal _options property.
Bump up node-txstatsd dependency
Merge pull request #55 from gwicke/master

Use node-txstatsd package for statsd logging
Improve statsd reports

- Better names:
    - use the path (including variables)
    - preserve wildcard segments
- Measure times in ms, as that's all statsd seems to support
Update dependency versions
Deal with errors in the Parsoid response
Fix handler loading by passing in the options to fromDirectories
Fix port in example config

Make sure it matches the default port in the code.
Use JSON values for data-parsoid and data-mw

This ensures that both are valid JSON. Each incoming value is parsed &
serialized. Outgoing values are currently also parsed for ease of further
processing, but we might eventually want to add an optimization that avoids
this for faster reads, possibly by passing something like an Accept header.
Merge pull request #56 from gwicke/master

Improve statsd reports
Drop dead code
Drop unnecessary calls to checkResponse
Pass the (required) apiRes.rev directly
Disambiguate conditional
Improve statsd logging further

- Record timings for each class of status codes separately. Graphite will also
  present a count & rate for each timing, so we can plot those & use them for
  thresholds.

- Use node-txstatsd's new ability to send multiple timings in one packet.
Fix revision table creation

Somehow we were running without a revision table for a while now, with a
fall-back request to the PHP API for each revision request.

This patch fixes the breakage first, better tests in a follow-up.
Merge pull request #61 from gwicke/unbreak_rev_table

Fix revision table creation
Merge pull request #59 from gwicke/statsd_improvements

Improve statsd logging further
Update node-txstatd package dependency
Update node-txstatd package dependency