[PATCH] tomcat.sh su support

[Paul Frieden <pf...@dChain.com>]

This is a patch to tomcat.sh that adds a -user flag to control who
tomcat executes as.  I couldn't get it to work by having it just execute
the java command as the new user, so I have the script execute itself as
the new user, and pass along the information it needs from the parent's
environment (JAVA_HOME, JAVACMD, etc).

I don't know if this is suitable for inclusion in one of the maintenance
releases, but I thought perhaps somebody would get some good out of it.

Paul Frieden