Number Format: Properly format Infinity and NaN.

Change numberSymbol()'s API to receive the symbol name instead of looking it up
itself. Therefore, numberFormat() properly formats infinite and nan.
Number: Implement parser

Fixes #248
Ref #200
README: Add number parsing content

Ref #248 #200
1.0.0-alpha.3
Plural: Create initial module

Borrow santhoshtr/CLDRPluralRuleParser.

Ref #220
Message: Create formatMessage

Also s/loadMessages/loadTranslations;
Unit: Create it