QPID-4463: [Java Broker] SimpleLDAPAuthManager - address review comments from Robbie Gemmell

* Ensure that trust stores used by auth managers cannot be deleted.
* Stop unnecessary dependency on jakarta-regexp when built by Ant.
* Make check for ldaps:/ check trim / case insensitive

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1536925 13f79535-47bb-0310-9956-ffa450edef68