* Invalid NSEC/3 bitmap on non-zero buffer
If the PackBuffer is used to encode an NSEC/3 record, the bitmap is
xored with the content of the buffer instead of being zeroed first.
The algorithm has been changed so it is able zero bytes without
losing too much performance (around 2x slower).
* Add some comments + rename some vars to make algo clearer
* Revert to previous algo with window length compute+0 on new window
* Use typeBitMapLen to compute the bitmap length to zero
* 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