Remove tldNamespaceAware property from mbeans-description file.
Add mention of tldValidation option to systemprops document, as it has been restored.

(Followup to r1513787, r1544585)

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1545749 13f79535-47bb-0310-9956-ffa450edef68
Align description of properties of StandardContext in mbeans-descriptors.xml with its Javadoc.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1545750 13f79535-47bb-0310-9956-ffa450edef68