Changes since 2.0.1

1) Reformat the code in define_firewall().

2) Reimplement dynamic zones.

3) Tweak new dynamic zone implementation.

4) Implement CONFIG_PATH.

5) Apply Stijn Jonker's fix for CONFIG_PATH.

6) Restore logic to make 'find_file' check for SHOREWALL_DIR separately.

7) Allow CONFIG_PATH to be inherited.

8) Fix ensure_config_path call.