ACCUMULO-1786 Use the PortUtils to get a free port for the test
Merge remote-tracking branch 'origin/1.4.5-SNAPSHOT' into 1.5.1-SNAPSHOT
Merge branch '1.5.1-SNAPSHOT'

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

Merging ACCUMULO-1786 is a no-op because of ACCUMULO-1664. Processes are
able to use random ports and MAC already does in 1.6.0-SNAPSHOT, so
there's no need to do anything special in the test.