They are outside of the module so can be called when the module is
disabled, which gives an error somewhere deep in the call stack.
Check for all endpoints whether saml2-idp is enabled in config
and whether the module is enabled before doing anything else.

Improve error handling

Fix ArtifactResolution due to misuse of Issuer

Convert to our wrapper class for assertions

post.* has been added directly under assets for now, tried it
via webpack but this added a several times overhead to these
very small files, so this seemed the cleanest solution for now.
But might be improved upon.

* 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

Old PHP templates are going to disappear anyway, so let's not break anything for a change that will be removed in the near future. We keep the .tpl.php extension though.

The old mail class uses the built-in `mail` function in PHP, and builds a payload by itself using hard-coded HTML and MIME-snippets. Let's use a library for that; PHPMailer has new dependencies and does all the heavy lifting.

These assets have been moved somewhere else or integrated as part of the new build system, so they are no longer used / necessary.

This resolves #1009.

This builds and minifies CSS and a common JS bundle, as well as copy the relevant fonts. In order to build, we now need to run "npm run build" after installing the dependencies with "npm install".

It's divided in three main pages, as the old interface: front/configuration, authentication/testing and federation. For now, only the front/configuration page is working.