ACCUMULO-3263 oh, right... namenode write ops are slow when done one-at-a-time
ACCUMULO-3244 add filename to bulk import report
Merge branch '1.6'

Conflicts:
	server/base/src/main/java/org/apache/accumulo/server/util/RandomizeVolumes.java
ACCUMULO-3263 forgot to shutdown the threadpool
Merge branch '1.6'
ACCUMULO-3286 Clean up some assertions in ConditionalWriterIT
ACCUMULO-3243 Remove explicit timeout on ShutdownIT
ACCUMULO-3243 Add missing defaultTimeoutSeconds and remove method-level timeout
Merge branch '1.6'
ACCUMULO-3296 If the stat for a node is null, it's already deleted. Quit.
Merge branch '1.6'
ACCUMULO-3292 Some extra information on flat out incorrect assertion failures.
Merge branch '1.6'