error_popup: protect all menu items from unexpected errors

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@655 d9718cc8-9f43-0410-858b-315f434eb58c
error_popup: protect all mouse events from unexpected errors

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@656 d9718cc8-9f43-0410-858b-315f434eb58c
error_popop: added a button for Exiting the program altogether

git-svn-id: https://micropolis.googlecode.com/svn/trunk/micropolis-java@657 d9718cc8-9f43-0410-858b-315f434eb58c