Move control of caching and linking options from the Context to the WebResourceRoot to enable them to by changed while the web application is running.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1553826 13f79535-47bb-0310-9956-ffa450edef68
Rename trace[d] -> track[ed]

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1553833 13f79535-47bb-0310-9956-ffa450edef68
Document the track locked files option

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1553838 13f79535-47bb-0310-9956-ffa450edef68