Use the MIT License

As part of our collaboration between jQuery Globalize, Moment.js, cldrjs and Wikipedia, it seems it would make things a lot easier if the CLDRPluralRuleParser project were licensed under MIT.

Contributors that have to sign off to re-license this project under MIT (<http://opensource.org/licenses/MIT>):

* [x] @santhoshtr (35 commits / 13,344 ++ / 818 --)
* [x] @Krinkle (5 commits / 10,386 ++ / 10,203 --)
* [x] @amire80 (3 commits / 215 ++ / 83 --)
* [ ] @brion (1 commit / 1 ++ / 1 --)
* [x] @rxaviers (1 commit / 19 ++ / 5 --)

There is one user not listed in contributors but listed in git log (@kartikm) who performed a merge.