ACCUMULO-2928 Add equals, hashCode and toString to batchwriterconfig.

Also includes some formatting changes. Includes some basic tests to make sure
hashCode and equals are functioning.
Merge branch '1.5.2-SNAPSHOT' into 1.6.1-SNAPSHOT

Conflicts:
	core/src/main/java/org/apache/accumulo/core/client/BatchWriterConfig.java
Merge branch '1.6.1-SNAPSHOT'

Conflicts:
	core/src/main/java/org/apache/accumulo/core/client/BatchWriterConfig.java