Empty key is treated as not exsisting

[jakubjafra]

Hi,

When I add empty key:

i18n.map('en', {
    key: ""
});

with option i18n.showMissing(true); the handlebars helper {{i18n 'key'}} is returning the key not empty string. Same goes to the i18n function. I think it's bug; and I just don't have time to write fix and make pull request on my own :)

Cheers