Migrated the data to an ActiveRecord database

used sqlite .dump with trivial hand-editing
Adapted the plotter to ActiveRecord
adapted fill-db to ActiveRecord
added the last two days
Fixed branch selection (--first-parent), applied to loc-1 measurements.
Enable concurrent database access (5s timeout).
Fixed creating repos and metrics.
Replotted with fixed branch selection also for zombies-1.

Measurements for yast2.rpm WIP.