Added additional stat types

- Added 'capabilities.json' which is basically a reverse cumulative
  'installations.json' to assist plugin developers in choosing base
  versions. Assumptions break down with backported API, but close enough.
- Added 'PLUGIN.versions.json' which contains the most recent month's
  distribution of versions of a specific plugin to assist administrators
  in making update decisions.

Minor changes:
- Ensure installations.json is based on latest month only. When I ran
  the script (no access to the raw stats), the DB contained all months.
  Not sure this is actually needed.
- Changed call order to place the long running process at the end.
Logging for the three extra stats files to see progress
Merge branch 'more-stats' of github.com:daniel-beck/infra-statistics into daniel-beck-more-stats
Merge branch 'daniel-beck-more-stats'
update jackson lib
move new number of installations per plugin to existing json, so a client using the numbers has all that belongs together at one place