ACCUMULO-778 (Configurable FATE threads in master) backport to 1.4 branch

git-svn-id: https://svn.apache.org/repos/asf/accumulo/branches/1.4@1435198 13f79535-47bb-0310-9956-ffa450edef68
ACCUMULO-919 backported to 1.4 branch

git-svn-id: https://svn.apache.org/repos/asf/accumulo/branches/1.4@1435288 13f79535-47bb-0310-9956-ffa450edef68