Downgrade externalized modules to a version that doesn't hold BC-breaking Webmozart-assertions

* updated catalan translations

* IDP configurable AuthnContextClassRef/AuthnContextComparison

* Add a few namespaces

* Externalize ldap

* Remove tests for LDAP-module

* Redirect old LDAP-class to ldap-module for backwards compatibility

Feature/add smtp mail

* Externalize negotiate

* Install pecl-krb5

We need to include this in our travis-tests as long as we include the negotiate-module in the release

look it up from the metadatadir from configuration variable

Instead of hardcoding the metadata directory, look it up from the metadatadir configuration variable