ACCUMULO-2560 fetch gc.threads.delete from configuration every time
ACCUMULO-2560 merge 1.6.1
ACCUMULO-2560 merge 1.6.1
ACCUMULO-3010 renamed test to conform to integration test pattern
ACCUMULO-3010 renamed test to conform to integration test pattern
ACCUMULO-3054 Create a metric for overall replication "health"
ACCUMULO-3055 Fix formatting
ACCUMULO-3055 Guard against failure due to multiple invocations of MAC.stop

MAC has allowed stop to be invoked a few times, so we want to ensure that we
don't start throwing an exception on multiple calls. There are also a few
race conditions (user invoking stop(), shutdown hook invoking stop(),
user invoking start again after MAC was stopped, etc) in which
we want to guard against this concurrency.

Adds synchronized to start and stop to ensure invocations of these
methods are exclusive and uses the `executor` member track start/stop
state. Adds a unit test to ensure multiple starts is an error, multiple
stops is not, reduces inline logging configuration, and applies
redirection to both surefire and failsafe tests.
Merge branch '1.5.2-SNAPSHOT' into 1.6.1-SNAPSHOT

Conflicts:
	minicluster/pom.xml
	minicluster/src/main/java/org/apache/accumulo/minicluster/MiniAccumuloCluster.java
	minicluster/src/test/java/org/apache/accumulo/minicluster/MiniAccumuloClusterTest.java
	minicluster/src/test/java/org/apache/accumulo/minicluster/impl/MiniAccumuloClusterGCTest.java
	minicluster/src/test/resources/log4j.properties
	pom.xml
ACCUMULO-3055 Add in missing license
Merge branch '1.5.2-SNAPSHOT' into 1.6.1-SNAPSHOT
ACCUMULO-3055 Fix the 1.6 test to verify what the current state is.
Merge branch '1.6.1-SNAPSHOT'
ACCUMULO-2560 Fix broken unit test
Merge branch '1.6.1-SNAPSHOT'
ACCUMULO-3048 Add in new fixes after rc0
Merge branch '1.5.2-SNAPSHOT' into 1.6.1-SNAPSHOT

Conflicts:
	CHANGES
Merge branch '1.6.1-SNAPSHOT'
ACCUMULO-3013 Remove unused import left behind.
ACCUMULO-2967 Remove warning from unused assignment