Adding JavaScript CLDR plural parser.

Adding JavaScript CLDR plural parser.

The JavaScript code of the parser was written by Santhosh.
The original project is hosted at GitHub:
https://github.com/santhoshtr/CLDRPluralRuleParser

Introduces resourceloader modules: mediawiki.cldr and
mediawiki.libs.pluralruleparser.

hi.js and ar.js removed since it has only convertPlural method. More [lang].js
needs to remove convertPlural, but not done in this commit.

The actual rules will be taken straight from CLDR and they are not
integrated in this commit yet.

Change-Id: I1aa3b081f4dad68515fd6cd46e4ab2dbdb3291eb