Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=54521
Ensure concurrent requests that require DIGEST auth receive unique nonces.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1443407 13f79535-47bb-0310-9956-ffa450edef68
Whoops.
Fix porting to Tomcat 7 issues in unit test

git-svn-id: https://svn.apache.org/repos/asf/tomcat/tc7.0.x/trunk@1443414 13f79535-47bb-0310-9956-ffa450edef68