Stop checking for proper xml header when detecting RSS and Atom feeds…

… — it’s often enough that the header is missing or is malformed. Add test case for https://www.fcutrecht.net/rss/rssfcutrecht.php which has a malformed header — <?phpxml version="1.0" encoding="UTF-8"?>

Revise failing test — the test was at fault.

Change to use a serial parsing queue to avoid thread explosions

Change the atom parser to use the related URL for the external link a…

…nd the alternate value for the permalink.

Change the atom parser to use the related URL for the external link a…

…nd the alternate value for the permalink.

Merge pull request #65 from Wevah/entity-fix

Re-encode special XML characters that aren't part of tags

Merge pull request #60 from stuartbreckenridge/main

RSParser as a swift package

Release 1.0