added summary of results for each distribution (per release status)

This essentially picks results of last version (with a given status),
and copies the results into the 'summary' field. When there are multiple
versions this makes it simpler to get 'current state'.
added summary of results for each distribution version

This essentially combines results from the 'stats' part, i.e. from all
machines and supported PostgreSQL versions.
option to disable excessive details by appending ?details=0 to the URI

Currently this is possible at two places:

* /distributions/{name} - disables overview of versions
* /distributions/{name}/{version} - disables per-machine results

In both cases it keeps the 'summary' with all results combined.