ACCUMULO-2465 Unit tests for BigDecimalCombiner

Add tests for min and max. Refactor setup into @Before method.
Add keys that won't combine to make sure all values are still correct.
Merge branch '1.6.0-SNAPSHOT'
ACCUMULO-2454 Improve Cobertura reporting

Coverage reports are now aggregated across modules. Also, the site reports exclude
Thrift-generated classes.
Merge branch '1.5.2-SNAPSHOT' into 1.6.0-SNAPSHOT
Merge branch '1.6.0-SNAPSHOT'
ACCUMULO-2472 update readme to list conditional mutations as part of API
Merge branch '1.6.0-SNAPSHOT'
ACCUMULO-2468 Add unit tests for o.a.a.core.data

Add unit tests for several classes. Convert from JUnit 3 to 4 where
appropriate. Fix bugs where new unit tests uncovered them. Replaced
assertTrue with assertEquals where possible.
Merge branch '1.6.0-SNAPSHOT'
ACCUMULO-2475 recovery failed due to using the wrong filesystem
Merge branch '1.6.0-SNAPSHOT'
Merge branch '1.6.0-SNAPSHOT' of https://git-wip-us.apache.org/repos/asf/accumulo into 1.6.0-SNAPSHOT
Merge branch 'master' of https://git-wip-us.apache.org/repos/asf/accumulo
Merge branch '1.6.0-SNAPSHOT'
ACCUMULO-2476, ACCUMULO-2342 Sleep after we modify a constraint. -- cherry-picked d4b06999 back to 1.4
Merge branch '1.4.5-SNAPSHOT' into 1.5.2-SNAPSHOT
Merge branch '1.5.2-SNAPSHOT' into 1.6.0-SNAPSHOT

Conflicts:
	proxy/src/test/java/org/apache/accumulo/proxy/SimpleProxyIT.java
Merge branch '1.6.0-SNAPSHOT'
ACCUMULO-2484 Allow the invoker of runTest to pass in a unique suffix
Merge branch '1.6.0-SNAPSHOT'