Add support for parentLocales

[natemueller]

Use the parentLocales section to figure out the correct fallback
locales. Can not use customization feature of I18n::Locale::Fallbacks
since it always places the default parent local before any customizations.

[camertron]

I don't really have approval rights here, but it looks good to me :)

[camertron]

Why lambdas and not regular 'ol methods?

[camertron]

Spelling: "ancestry"

[davispuh]

It seems like there's some bug

$ thor cldr:export

ruby-cldr/lib/cldr/export/data/parent_locales.rb:7:in `initialize': wrong number of arguments (given 1, expected 0) (ArgumentError)
from ruby-cldr/lib/cldr/export.rb:95:in `new'
from ruby-cldr/lib/cldr/export.rb:95:in `block in locale_based_data'
from ruby-cldr/lib/cldr/export.rb:94:in `each'
from ruby-cldr/lib/cldr/export.rb:94:in `inject'
from ruby-cldr/lib/cldr/export.rb:94:in `locale_based_data'
from ruby-cldr/lib/cldr/export.rb:88:in `data'
from ruby-cldr/lib/cldr/export/yaml.rb:11:in `export'
from ruby-cldr/lib/cldr/export.rb:70:in `block (2 levels) in export'
from ruby-cldr/lib/cldr/export.rb:69:in `each'
from ruby-cldr/lib/cldr/export.rb:69:in `block in export'
from ruby-cldr/lib/cldr/export.rb:68:in `each'
from ruby-cldr/lib/cldr/export.rb:68:in `export'
from ruby-cldr/lib/cldr/thor.rb:27:in `export'

def locale_based_data(component, locale, options = {})
        data = locales(locale, component, options).inject({}) do |result, locale|
            data = Data.const_get(component.to_s.camelize).new(locale)

it calls ParentLocales.new(locale) which doesn't take any argument.

[camertron]

@davispuh Oops, my bad! I don't use thor cldr:export so I didn't notice it was broken. #40 should fix it :)