ACCUMULO-1971 Clean up agitator scripts for clarity and ease of multi-user systems.

Squashed commit of the following:

commit ff62ce94dd72e19386f773d52ab3fc52cf8e2609
Author: Josh Elser <elserj@apache.org>
Date:   Fri Dec 20 14:05:58 2013 -0500

    ACCUMULO-1971 Fix the invocation of the agitator scripts to account for the removal of the (unnecessary) user argument.

commit 3c0969856741d6404553974b0a558c318d42a1f8
Author: Josh Elser <elserj@apache.org>
Date:   Wed Dec 18 00:33:00 2013 -0500

    ACCUMULO-1971 Change the logic to kill a tserver and datanode each time.

    Previously, when this functionality was in the same perl script, 33% would restart the tserver, 33% would restart the datanode and the
    remaining would restart both. Since we can't reliably determine this, every cycle of the agitator will kill and restart
    a process (datanode and tserver) but they may not be on the same host.

commit 780def9cdc91c65fd9f678f198c20150373d1eec
Author: Josh Elser <elserj@apache.org>
Date:   Wed Dec 18 00:32:45 2013 -0500

    ACCUMULO-1971 Remove the unnecessary user arguments.

commit d730c4b7206b5e9a8d847ba0a5bcd8f7ef88cee1
Author: Josh Elser <elserj@apache.org>
Date:   Tue Dec 17 23:32:21 2013 -0500

    ACCUMULO-1971 Split up the agitator script into discrete Accumulo and Hadoop components to remove all of the
    user-changing shenanigans.
Merge branch '1.5.1-SNAPSHOT' into 1.6.0-SNAPSHOT