Migrate the logout handlers to namespaces, change the base abstract class to be an interface instead.

Migrate all the logging handlers to namespaces. Make SimpleSAML\Logger a bit more intelligent so that it allows using custom logging handlers. Now you just need to implement SimpleSAML\Logger\LogginghandlerInterface in a class, and set the 'logging.handler' option in the configuration file to a string with the full name of your class.

Fix build. If we are logging to STDERR, we don't have to write to the filesystem anyway, so why checking?

If we are invoked from the command line, log the messages to standard error, instead of ignoring them.

Since we allow now defering log messages while we are initializing logging, we no longer need to dump them to the error log.

Allow passing as a parameter the logging handler to use in SimpleSAML\Logger::createLoggingHandler().

Creating a session doesn't seem the way to NOT create a session. Stop creating a transient session, it only causes trouble.

This is related to #346, and closes #347. It enables richer NameIDPolicy configuration, allowing to set not only the format, but also the value for "AllowCreate".

Move SimpleSAML_Metadata_MetaDataStorageHandlerMDX to SimpleSAML\Metadata\Sources\MDQ, and stop referring to it as MDX elsewhere.

Fix missing curly bracket

Fixes: Mar 25 11:06:53 simplesamlphp INFO [0015a148dc] Template: Looking up [{login:processing]: not translated at all.

Add Greek support

Crude translation

"Vette pech" (fat chance) appears to offend some of our users. The translations for these seem to vary wildly:
* dr: "pas de chance" (no luck)
* de: "Tut uns leid" (we are sorry)
* it, da,... : this part is left out. This is the best option in my opinion.

Fix typo + authentication-failure on empty attributes-array

An empty array shouldn't lead to an aborted logon.
Example when we try to get the 'mail' attribute:
UserA has a value set in the mail-attribute and passes the test -> Negotiate logon succeeds
UserB has an empty mail-attribute and fails the test -> Negotiate logon fails and the user has to log on manually (fallback to LDAP is initiated)

Be graceful if a SAML assertion does not contain a NameID. Do not set it in the state array, and set logout as "saml1" to avoid SLO, since SLO requires NameIDs.