Fix Locale; If a Twig-variable is not set and then translated, these methods are called with a null parameter

* Remove deprecated classes

* Remove support for certificate fingerprints

* Remove many deprecated methods and pieces of code

* Remove SAML1.1/Shib1.3 support

* Remove many superfluous annotations

* Update unit test to work with new PHPunit

Closes #1268 
Closes #1020 
Closes #431 
Closes #167 
Closes #151 

* Migrate assertions to Webmozart

* Upgrade saml2-library to v4

* Stop considering Issuer-strings

* Stop considering NameID-arrays

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

Broken during refactoring in 6607b7fb

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

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.

Fixes #1270

* 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>

* 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