* Migrate assertions to Webmozart

* Upgrade saml2-library to v4

* Stop considering Issuer-strings

* Stop considering NameID-arrays

* Bump to PHP 7.2

This makes it mirror how it used to work and how the twig templates
work. The solution is not pretty, but the longer term solution is to
just get rid of the oldui exception.

Also actually run the existing EMail unit tests. That might have
caught this.

Closes: #1269

Closes: #1275

Broken during refactoring in 6607b7fb

Non-file-upload crashed on Symfony request building.
File upload crashed because of not using the actual path.

In the modern template also clean up HTML a bit.

Add a common use case to add entity categories - until now it's
hard for users to find SSP examples for how to do it.

Different from the other options, setting it to null does not use
a default but throws an error if you enable metadata signing, so
enabling metadata signing in the default config will throw an
exception. Better to just leave it out, the option is documented
but should not be necessary for most installs, so needs not be
in the template.

We moved to Codecov

People might do this in the past to get correct metadata (thereby
breaking other email related functions). But our metadata generator
will now take care of this, so we can just ignore any mailto: prefix.

The testsuite already confirms this behaviour.

After logout, you would be redirected to a non-existent path (404).
Likely the best place to be redirected after logout is the base.

Template would fail because key does not exist, when default() is
not immediately after it. So need to split this up.

Fixes #1270

#3d1210 switched from using phpunit annotations to `expectException ()` for asserting expected exceptions, but the documentation still mentions the annotation.

* Use strict variables in Twig, except for our TemplateTest; throw exception on missing variables

* Fix issues due to Twig strict_variables=true

* Fix for #1229

* Fix metadata-template

* Added Kernel class to handle request

* Kernel handle request

Kernel is loaded in SimpleSAML\Module class
Removed Router and ControllerResolver classes

* Added route command (squash)

* Use symfony application and cache

* Updated to today's standards

* Fix for Symfony4 & Catch environment from ENV variable

* Standardize location of routes/services files

* Trying to make slashes work properly in all situations

* Convert XML to YML

* Fix some template-names and endpoints

* Rename Controller-classes

* Update dependencies

* Fix routing files

* TooManyArguments

* Fix TypeCoercion

* PSR-12

* Fix rebase mistake

* Rebase lock-file

* Fix Psalm

* Add strict_types declaration

Co-authored-by: Sergio Gómez <decano@gmail.com>

This reverts commit 6cfdef4d.

This reverts commit 924e825e.