Export distributables as modules

- cldr.js: Core library;
- cldr/unresolved.js: Provides inheritance support for unresolved data;
- cldr/supplemental.js: Provides supplemental helper methods;
Check for supplemental on both _resolved and _raw

Parent Lookup first try to find for parent information on supplemental
data. In order to do so, it can't use the instance method cldr.get(), or
it could run into an infinite loop. Therefore, it direct accesses the
supplemental data via resourceGet on both objects: Cldr._resolved, and
Cldr._raw. Previously, it wasn't checking Cldr._raw though. Fixed.
Make comments more clear
Allow tests to log