* APL record: add structure and code point
* APL record: add wire format support
* APL record: add presentation format support
* APL record: add isDuplicate implementation
* APL record: add copy implementation
* APL record: add len implementation
* APL record: run go generate
* APL record: fix condition checking for equality
* APL record: use switches to map family to address length
* APL record: check bounds of individual fields rather than whole header
* APL record: stylistic changes
* APL record: remove APLPrefix methods from public interface
* APL record: update README
* APL record: additional cleanup for code review
* APL record: change return type from pointer to struct
* APL record: refactor of pack and unpack to eliminate extra variables