* Support metadata XML directly in config
Also consider 'xml' as a key, in addition to 'url' and 'file'.
When provided, attempt to load this directly as a metadata XML string.
This is useful when working with dynamic configuration and external polling of metadata updates.

* Test loading XML from a fixed string
No preexisting test in this area
Adjust XML loader to only get global config in file mode - otherwise it is
unused, and it might pollute the test usage.
Test that an actully invalid config throws an exception, but that minimal valid
(albeit useless) XML is accepted.

The use of count function is wrong and unnecessary. If the array is
empty the foreach loop will not run.

Fixes https://github.com/simplesamlphp/simplesamlphp/issues/818

forward-port of my recent fix in branch 1.15

Fixes issue https://github.com/simplesamlphp/simplesamlphp/issues/793

All descendants overload this function anyway

Also fixes edge-case situation where $_SERVER['SERVER_PORT'] is not set for an HTTPS connection, this function would return an explicit port 80 i.e. ":80" rather than an empty string.

Call to undefined method Memcached::getExtendedStats()

This reverts commit 9ad60fe1.

Psalm is starting to get annoying. Both openssl_decrypt() and realpath() can return a string or false on error. Psalm seems to ignore the latter all of a sudden, so it assumes the returned variable will always be a string and then it fails when you check on errors. This fix explicitly declares the problematic variables with types string or false, so that psalm stops complaining.

Scrutinizer:
The expression $result of type array is implicitly converted to a boolean; are you sure this is intended? If so, consider using empty($expr) instead to make it clear that you intend to check for an array without elements.

setupTwigTemplatepaths() cannot return false