Fixed "TypeError: Invalid attempt to destructure non-iterable instance. In order to be iterable, non-array objects
must have a Symbol.iterator method." error caused by en-US format change in IANA time zone update.
Added a limited IE 11 support. All local time zones there have zero offset.
Changed distributive file format from ES6 modules to ES5-compatible transpiled scripts. Client applications no longer
need to transpile the library explicitly, i.e. they don't need to customize Babel configuration for this purpose.