Creates an lookup table map object for the specified option or the default value
function createLookupTable(option, default_value, extend) {
			var value = settings[option];

			if (!value) {
				// Get cached default map or make it if needed
				value = mapCache[option];

				if (!value) {
					value = makeMap(default_value, ' ', makeMap(default_value.toUpperCase(), ' '));
					value = tinymce.extend(value, extend);

					mapCache[option] = value;
				}
			} else {
				// Create custom map
				value = makeMap(value, ',', makeMap(value.toUpperCase(), ' '));
			}

			return value;
		}