stream: Fix typo.
stream.hls: Fix docstring formatting.
stream.http: Fix docstring formatting.
utils: Safer error formatting in parse_json/xml.

Resolves #440.
docs: Switch theme to my forked version of the RTD theme.
docs: Some tweaks and rewordings.
docs: Update theme so it actually works on RTD.
docs: Minor theme tweaks.
Update CHANGELOG.rst.
docs: Hide the RTD badge, it seems I broke it anyway.
docs: Fix JS issue.