Fixing use of implementation class instead of interface
Adding generic toString() method for persisted objects
Correcting instantiation of subclass, adding tests
Properly generating exceptions including causes
Returning the correct number of stream alerts per stream now
Disabling validation of value field for field presence rule
Use ES index prefix on deflector, fixes #489
use sane default config variables for the new output batching, fix docs. fixes #571
Make flush interval of batched ES output configurable. Defaults to 1s.

We really need to change Periodicals to have runtime intervals with
millisecond precision.
Adding tunable for the batched output flush interval and explanation
new API call: terms stats
change termsstats response a bit
facetfilter for termsstats API was missing
fix typo
serialize NodeID to String in MonogDB to fix dead letter queuing
Move getDefaultRestTransportUri() to BaseConfiguration.

Allows reuse for graylog2-radio.
Improve rest_transport_uri default value for graylog2-radio.

If not set, use the value of rest_listen_uri. Add exception if
rest_listen_uri is 0.0.0.0 to use the first non-loopback IPv4 address.

Related to #577.
Remove config that was committed by accident.
Update rest_transport_uri description in radio example config.
Order terms stats by mean time