Use ES index prefix on deflector, fixes #489

(cherry picked from commit 84813ab619e8dba994e3cdc5b4eafd3ae75c908e)

Conflicts:
	graylog2-server/src/main/java/org/graylog2/indexer/Deflector.java
	graylog2-server/src/main/java/org/graylog2/indexer/healing/FixDeflectorByDeleteJob.java
	graylog2-server/src/main/java/org/graylog2/indexer/healing/FixDeflectorByMoveJob.java
	graylog2-server/src/main/java/org/graylog2/periodical/DeflectorManagerThread.java
use sane default config variables for the new output batching, fix docs. fixes #571

Conflicts:
	graylog2-server/src/main/java/org/graylog2/Configuration.java
	graylog2-server/src/main/java/org/graylog2/periodical/BatchedElasticSearchOutputFlushThread.java
Adding tunable for the batched output flush interval and explanation
Make flush interval of batched ES output configurable. Defaults to 1s.

We really need to change Periodicals to have runtime intervals with
millisecond precision.

Conflicts:
	graylog2-server/src/main/java/org/graylog2/Configuration.java
	graylog2-server/src/main/java/org/graylog2/periodical/BatchedElasticSearchOutputFlushThread.java
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.

Fixes #577.
do not omit Integer, Float and Character valued fields from RadioMessage

not complete yet, needs additional tests for release

issue #579
add test for RadioMessage.serialize

fixes #579
Fix port in graylog2-radio rest_transport_uri example.
bump version to 0.20.3
merge of 0.20.3 from origin