* Updated era data format in supplementalData.
* Include tentative era names in data. Implemented Japanese era loaded from CLDR data in ICU4J.
* ICU4C implementation, ICU4C refactoring. WIP.
* VS project updates and some bug fixes
Also added API comments.
* Review feedback and bug fixes
- NULL to nullptr
- use of LocalUResourceBundlePointer
- TYPO "name" to "named"
- env var checking stricmp() == 0
* API comment correction based on feedback
* Duplicate the comment in ucal.h to calendar.h
* Fixed spelling errors in API comment
