ISO 3166 Country Name / Code Mapper in Javascript

Uses the data in http://www.iso.org/iso/country_names_and_code_elements_txt to map from
country codes to country names and vice versa. Also provides lists of all names and codes.

## Overview

- exports.getCode()
- exports.getName()
- exports.getAllCodes()
- exports.getAllNames()

exports.getCode(English:String)

Get a country code for a country name. Case-insensitive.

Examples:

``js
// Returns 'CH'
countrynames.getCode('Switzerland')
// Returns 'BB'
countrynames.getCode('BarbaDOS')
`

exports.getName(Two-letter:String)

Get a country name for a country code. Case-insensitive.

Examples:

`js
// Returns 'TONGA'
countrynames.getCode('TO')
// Returns 'RÉUNION'
countrynames.getCode('re')
`

exports.getAllCodes()

Get a country name for a country code. Case-insensitive.

Example:

`js
// Returns an array ["AD", ... "ZW"]
countrynames.getAllCodes();
`

exports.getAllNames()

Get a country name for a country code. Case-insensitive.

Example:

`js
// Returns an array ["AFGHANISTAN", ... "ZIMBABWE", "ÅLAND ISLANDS"]
countrynames.getAllCodes();
``