Make constant used as part of the build of the accept header private.

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1551380 13f79535-47bb-0310-9956-ffa450edef68
Add assertEqualsIgnoreCase for strings.

git-svn-id: https://svn.apache.org/repos/asf/jena/trunk@1551381 13f79535-47bb-0310-9956-ffa450edef68