Fixed typo introduced by #1008

class_implements() returns class names without leading backslash

For Redis instances that require authentication, the current Redis store does not work.  So, this commit adds optional support for utilizing the Predis password option.  It will pick up the password from the config file and pass it along when it instantiates the Predis client.

The test simply checks that adding the password option doesn't break the constructor. Since Predis parameters end up as protected, we can't verify that the instance contains the password.

This reverts commit 9fa3dc94.

Start migrating to SAML2 getters/setters

This resolves #1009.

We were echoing the result of require(), resulting in a '1' being printed during login

This introduces a "theme.header" configuration option in order to achieve that.

This function can be used to load an asset from a twig template, adding a "tag" parameter to it with a few dynamic bytes depending on the version of SimpleSAMLphp, or the last modification time of the file if we are running master. This behaves as a cache-buster, forcing browsers to reload assets when a new version of SimpleSAMLphp gets installed.

This way we can forget about updating the copyright notice every year.

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.