Revisits logging in ElectionState and ClusterConfiguration

Commit 956dc3e1a8edd91a2a3710e2c71326b16a849de7 added some extra
 logging in ElectionState and ClusterConfiguration in order to hunt
 down a bug. It turns out this logging is useful to keep in production
 too. This commits sets proper levels, cleans it up a bit.

Cleans up some superfluous casts that appeared in the code.

Conflicts:
	enterprise/cluster/src/main/java/org/neo4j/cluster/protocol/cluster/ClusterConfiguration.java
	enterprise/cluster/src/main/java/org/neo4j/cluster/protocol/election/ElectionState.java