Note: I don't know if this is the right Stack Exchange site for this. If there's a better one, tell me in a comment and I'll move it there.

I want to use Unicode emoji icons (U+1F300..U+1F5FF) in a free, open-source instant messaging app. I considered using FontAwesome icons, but their icon set is too small (not enough faces for :), :O, :P, etc.). Then I wanted to use Segoe UI Emoji, but that's copyrighted and expensive, as it's owned by Microsoft.

Are there any free Emoji-complete fonts? If so, what are they?