ACCUMULO-2060 Add a better defaults to the classloader defaults.
Merge branch '1.4.5-SNAPSHOT' into 1.5.1-SNAPSHOT

Conflicts:
	src/start/src/main/java/org/apache/accumulo/start/classloader/AccumuloClassLoader.java
ACCUMULO-2312 NPE fixed by 2316/2318, but making message better
Merge branch '1.5.1-SNAPSHOT' of https://git-wip-us.apache.org/repos/asf/accumulo into 1.5.1-SNAPSHOT
Merge branch '1.5.1-SNAPSHOT' into 1.6.0-SNAPSHOT
ACCUMULO-2317 Missed these errors
ACCUMULO-2248 properly catch wrapped NamespaceNotFoundException in concurrent
Merge branch '1.6.0-SNAPSHOT' of https://git-wip-us.apache.org/repos/asf/accumulo into 1.6.0-SNAPSHOT