[1061311] rhqctl contains user modifiable values that result in an unsupported rhqctl script
Add logic to 'rhqctl upgrade' command to copy rhq-server-env.sh|bat from the
old to new server, if it exists.  The old, potentially edited, version will
be used and the new version will be backed up for reference in case it has
new env variables and/or documentation.  This behavior is analogous to what
we currently do for rhq-agent-env.sh|bat during an agent update.

Also: fix an upgrade problem with server stop at the end of the upgrade.