Update doc references to refer to CLDR and the page of CLDR codes where
appropriate - it used to say ISO country codes were used, but they aren't.
Also updated to refer to two *or three* letter language codes since they may be three letters (we use the shortest defined one for a language)
Updating comments about leadingDigits field at territory level as well.
- LOGGER -> logger
- Small comment fixes
- Style-guide-recommended formatting changes
- Removal of duplicate, unneeded method in PhoneNumberToTimeZonesMapper.java for canBeGeocoded, using phoneNumberUtil instead.