[FEATURE] FLOW3 (I18n): Add real CLDR inheritance and alias support.
CLDR files are now parsed to slightly different array structure which
is much more useful and simplifies many code fragments. This change
also allowed to write simple but pretty complete inheritance support
as defined in CLDR specification, and support for alias tag. However,
for the latter one, only source attribute set to 'locale' is supported
(most of the cases anyway).
CldrModelCollection class was deleted; now CldrModel class covers both
use cases for these both classes.