[Fri Nov 29 17:35:43.942472 2013] [core:warn] [pid 14655] AH00111: Config variable ${APACHE_LOCK_DIR} is not defined
This message is displayed because you directly executed the apache2 binary. In Ubuntu/Debian the apache config relies on the envvar file which is only activated.

If you start apache with the init script or apachectl.

Your original problem is that you have no a proper hostname (fqdn) for your machine.

If you can't change it, change the ServerName variable in /etc/apache2/apache2.conf to localhost or your prefered FQDN.