Redefine globalXsltFile as relative to CATALINA_BASE/conf or CATALINA_HOME/conf

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1578610 13f79535-47bb-0310-9956-ffa450edef68
Prevent user supplied XSLTs from defining external entities

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1578611 13f79535-47bb-0310-9956-ffa450edef68