This reverts commit dabe7e47.

Now also considers any attributes.po in the configured theme, if any.
Makes the attributes.extradictionary config setting obsolete.

This commit consists of patches automatically generated for this project on https://scrutinizer-ci.com

* Raise minimum PHP version to 7.0

* Remove tests pre-PHP 7.2

* Upgrade dev dependencies

* Ignore tests for deprecated class

* Add typehints; not touching public API

* Remove none-array replacements-param; old behaviour from pre-1.4 release

* Psalm fixes

* Add upgrade notes

* PSR-12

PSR-12 compliancy

This is something the developer of a module is supposed to deal with. If you are just using SSP, it doesn't make much sense to have your log files flooded by errors about missing translation files or directories, since you cannot do anything about it and the original english text will be used anyway.

Create a new "configpage" hook for those modules that need to inject anything in the configuration page.

This allows us to change the signature of the hook, so that we pass it the \SimpleSAML\XHTML\Template object and then the hook can not only add data to be passed to the twig template, but also add its own translation domain. This was needed because many modules were putting their translations inside "core", and when moving those to the modules themselves, the new translation system cannot perform the translation because only the translations for the current module in use are loaded (in the config page, that's the core module). Therefore, we needed a way to get the Localization instance from the template, and a way to pass that to the hook so that the hook can register the translations for its own module.

Twig will always use gettext, legacy will use legacy. Twig does not
work with legacy so new ui would break if you would not also set this
option. Instead, just switch the system in use based on the usenewui
config variable.