ACCUMULO-2163 made MAC always run GC
Merge branch '1.4.5-SNAPSHOT' into 1.5.1-SNAPSHOT

Conflicts:
	minicluster/src/main/java/org/apache/accumulo/minicluster/MiniAccumuloCluster.java
Merge branch '1.5.1-SNAPSHOT' into 1.6.0-SNAPSHOT

Conflicts:
	minicluster/src/main/java/org/apache/accumulo/minicluster/MiniAccumuloCluster.java
	minicluster/src/main/java/org/apache/accumulo/minicluster/MiniAccumuloConfig.java
	minicluster/src/test/java/org/apache/accumulo/minicluster/MiniAccumuloClusterGCTest.java