Fixed bug in tests for statsd backend tests.
Added the option to define a topic.
Fixed bug in disabled backends.
Some improvements.
Metricdb buffering.
updated to new metricdb.
Added support for multiple metricdb connections.
Merge branch 'test' of https://github.com/luceracloud/tachyon-aggregator into test
Fixed reltool deps.
Merge branch 'test' into dev