ACCUMULO-2382 make agitation work with a non-default CONTINUOUS_CONF_DIR.

* Change start-agitator to use inferred installation directory instead of passed in conf dir.
* Ensure tserver and master agitator default ot ACCUMULO_HOME if present, so that starting all as root works.
Merge branch '1.5.2-SNAPSHOT' into 1.6.0-SNAPSHOT
ACCUMULO-2382 make continuous ingest test mapreduce jobs work with non-default CONTINUOUS_CONF_DIR
Merge branch '1.6.0-SNAPSHOT'
ACCUMULO-2507 add debugging information, and timeout for reader thread to pull in all the output of the tserver
Merge branch '1.6.0-SNAPSHOT'
ACCUMULO-2508 Add delay after dropping user in security randomwalk
Merge branch '1.4.5-SNAPSHOT' into 1.5.2-SNAPSHOT

Conflicts:
	test/src/main/java/org/apache/accumulo/test/randomwalk/security/DropUser.java
Merge branch '1.5.2-SNAPSHOT' into 1.6.0-SNAPSHOT
Merge branch '1.6.0-SNAPSHOT'

Conflicts:
	test/src/main/java/org/apache/accumulo/test/randomwalk/security/DropUser.java