New supporting script, helpful if you want to run Tomcat (catalina) wrapped up in 'xvfb-run' (X-based Unix systems such as Linux), such as is needed for WebSwing. xvfb allows for graphical rendering processes even when a headless server, and is a feature of the webswing-server.war file that a Linux server needs to make use of, when the terminal window in which Greenstone3/Tomcat is being runing from (e.g. ant start), is not capable of displaying a graphical window. To connect 'xvfb-run' to the moment in catalina.sh where the 'java' command is executed to run java, define the environment variable _RUNJAVA to be 'xvfb-run-java' ... when undefined it defaults to be just 'java'
