if there is more than one subtitle for the language, use the first one
Add Patreon extractor
Add import for Patreon extractor
fix exception
Fix CSS parsing for Patreon

Some of the CSS classes end in " double", so this commit refines the
HTML parsing to account for both kinds of classes, and also adds an
additional test case.
Merge remote-tracking branch 'terminalmage/add-patreon'
[patreon] Simplify (#3390)
Credit @terminalmage for patreon (#3390)
Merge remote-tracking branch 'liudongmiao/patch-subtitle'