Fix for issue #963; implements a -port auto command-line option to setting the the embedded Tomcat server to run on an open port.  JUnitShell always runs on port auto.

Patch by: tobyr, scottb
Review by: bruce, scottb


git-svn-id: https://google-web-toolkit.googlecode.com/svn/trunk@966 8db76d5a-ed1c-0410-87a9-c151d255dfc7