Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=49018

Fix https://issues.apache.org/bugzilla/show_bug.cgi?id=49018
Fix processing of time argument in the "Expire sessions" action in the Manager web application

Also, provide separate templates for the "managerServlet.sessiontimeout" message, to allow it to be properly translated into other languages. I cannot provide the actual translations, though. The translated variants of the new messages are now a mix of English and translated text, which just mimics the old behaviour.

git-svn-id: https://svn.apache.org/repos/asf/tomcat/trunk@931415 13f79535-47bb-0310-9956-ffa450edef68