GlobalizeCompiler does not work unicode extensions in locales.

As per http://www.unicode.org/reports/tr35/#Locale_Extension_Key_and_Type_Data a locale should be able to handle unicode extensions such as

- ca (Calendar algorithm)
- cf (Currency format style)
- co (Collation style)
- cu (Currency type)
- em (Emoji presentation style)
- fw (First day of week)
- hc (Hour cycle)
- lb (line break style)
- lw (line break word handling)
- ms (measurement system)
- nu (numbering system)

Now, I know many of these options are not supported by Globalize, but I know we can atleast handle -u-nu (numbering system), -u-cu (currency type) and -u-cf- (currency format style)

When running this in the Globalize compiler, there is an assumption that the passed in locale would match the CLDR directory structure.

```
➜ node-sandbox ./node_modules/.bin/globalize-compiler -l ar-EG-u-nu-latn -o dest.js app.js
fs.js:808
return binding.readdir(pathModule._makeLong(path));
^

Error: ENOENT: no such file or directory, scandir '/home/site/ExternalRepos/node-sandbox/node_modules/cldr-data/main/ar-EG-u-nu-latn'
at Error (native)
at Object.fs.readdirSync (fs.js:808:18)
at jsonFiles (/home/site/ExternalRepos/node-sandbox/node_modules/cldr-data/index.js:36:22)
at /home/site/ExternalRepos/node-sandbox/node_modules/cldr-data/index.js:60:21
at Array.reduce (native)
at mainPathsFor (/home/site/ExternalRepos/node-sandbox/node_modules/cldr-data/index.js:59:18)
at Function.cldrData.entireMainFor (/home/site/ExternalRepos/node-sandbox/node_modules/cldr-data/index.js:90:29)
at cldr (/home/site/ExternalRepos/node-sandbox/node_modules/globalize-compiler/lib/compile-extracts.js:30:57)
at Object.compileExtracts (/home/site/ExternalRepos/node-sandbox/node_modules/globalize-compiler/lib/compile-extracts.js:55:18)
at Object. (/home/site/ExternalRepos/node-sandbox/node_modules/globalize-compiler/bin/globalize-compiler.js:82:28)

```

How should I resolve this? The problem is that when using Globalize with the globalize-compiler and the webpack plugin, we are assuming that the locale passed to Globalize matches the CLDR data directory.

Any guidance would be helpful.