Content length is managed internally as a long. Fix a few places that were unnecessarily restricting it to an int.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1517970 13f79535-47bb-0310-9956-ffa450edef68
Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=55383
Set the mime-type to prevent an error when viewing the changelog directly.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1517973 13f79535-47bb-0310-9956-ffa450edef68
Fix comment

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@1517980 13f79535-47bb-0310-9956-ffa450edef68