Fallback on translate_file does not work

[schancel]

Fallbacks for translate_file don't work correctly:

Liquid Exception: Included file 'xxx/features.html' not found in /Users/xxx/xxx/_i18n/es directory in index.html

[joshcummingsdesign]

I had the same experience. I submitted #130 to resolve this issue. I believe that if content doesn't exist in the target language, it should fall back to the default language.