BUG-1796: implement SourceIdentifier/PotentialSchemaSource caching

Adds a global cache for both object types and uses it in the
AbstractSchemaSourceRepository.

Change-Id: I87ff4e5379a6d0f3b39f56d8d2197571cfa9325d
Signed-off-by: Robert Varga <rovarga@cisco.com>
Bug 1719 - Formatting number in DurationStatsTracker

- added format method which uses dot separator independently of default
  locale

Change-Id: Ia5447f56cab49ccdba7676516199d6bdaf84daf2
Signed-off-by: Ladislav Borak <lborak@cisco.com>
Merge "BUG-1796: implement SourceIdentifier/PotentialSchemaSource caching"