...
CATALINA_OPTS="$CATALINA_OPTS -Djava.library.path=/usr/local/Cellar/tomcat-native/1.1.30/lib"
Further, in order to reduce some memory errors that your bound to run into, bump up the memory settings (-Xms512m -Xmx512m -XX:MaxPermSize=256m), so combined it becomes:
CATALINA_OPTS="$CATALINA_OPTS -Xms512m -Xmx512m -XX:MaxPermSize=256m -Djava.library.path=/usr/local/Cellar/tomcat-native/1.1.30/lib"
Edit your tomcat server.xml config, to let it know about the DSpace webapps that will be there.
...