QPID-4463: Corresponding updates to Java Broker docbook

* Document truststore name field

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1536122 13f79535-47bb-0310-9956-ffa450edef68
NO-JIRA: [Java Broker docbook] Improve documentation for SimpleLDAPAuthenticationProvider

Brought together the two security warnings.  Noted that LDAP search utilises sub-tree search.
Noted that password goes to Directory in the clear. Corrected a couple of typos.

git-svn-id: https://svn.apache.org/repos/asf/qpid/trunk@1536123 13f79535-47bb-0310-9956-ffa450edef68