v1.8.1 - Player and transcript fixes

Fixed

• Watch and Listen could stop working after updating to 1.8.0 on sites behind a page cache or CDN (such as Cloudflare), because an older copy of a player file was still being served.
• After updating, clear your site's page cache (including any cache your web host runs), your CDN cache (such as Cloudflare), and your browser cache.
• YouTube transcripts imported after updating now show symbols such as & and quotes correctly instead of codes like &. To fix a transcript imported earlier, delete it and import it again.
• Imported transcripts no longer lose words or lines when symbols are cleaned up, and symbols such as < and > in transcripts now show on the sermon page.
• If a YouTube transcript can't be fetched, CP Sermons no longer saves an empty transcript, and Import from YouTube on the sermon edit screen shows an error.

Improved

• Player files are now requested with a version number, so future updates won't load an old cached copy.