Changelog updates
Changelog updates

- Added 27 Brazil calendars -- thanks a lot to @luismalta & @mileo, (#409 & #415),
- Fixes and additions to some calendars -- again, thanks to @luismalta & @mileo, (#409 & #415)
- Added an IGBE_REGISTER to reference IGBE (brazilian) calendars with related tests (#415).

novafloss/workalendar,jaraco/calendra,novapost/workalendar