Added base debug info.

Activated by visiting any Twitch page and adding
`#twitch-chat-emotes-debug` to the end of the URL.
Allow non-`chansub` emotes

This opened an opportunity to change the logic behind how getting usable
emotes works. Checks emote URLs instead of relying on `emoticon_sets`.
Fixes an error on non-standard subscription channel names. Fixes #20 as
`userInfo.emoteSets` is no longer used.
Version bump