* Update MathJax URL to use version 2.7.5
* Piwik was renamed to Matomo

Only OIDC providers that support configuration discovery are supported.

A log file path can now be set via `arsnova.log.file` Java system
property. If a log file path is set, the threshold for STDOUT logging is
increased to WARN.

Support for java system properties to tune logging have been added:
* arsnova.log.exceptions
* arsnova.log.level
* arsnova.log.level.root
* arsnova.log.level.spring
* arsnova.log.properties

Consistently use singular for packages which contain mixed kinds of
classes. Moved a few classes to packages that better fit them.

We now use the format property instead as type ID for Jackson. A custom
TypeIdResolver is used for the mapping.

Entities can now be retrieved interally without authorization checks. In
this case, the entity is marked for internal use and serialization is
prohibited.

This fixes get for multiple IDs and find.

* AuthenticationProvider-agnostic User object allows access to common
  user attributes: userId, loginId, authProvider, etc.
* Auto-create UserProfiles for external accounts
* Use userId (instead of loginId) for permission checks
* Use custom implementation for Pac4j integration
  (remove org.pac4j.spring-security-pac4j)
* Move authentication logic from controller to service layer
* Remove user room role handling
* Rename targetDomainType 'session' to 'room'

Use `authProvider` + `loginId` instead of `username`.

A new service, repository and entity have been introduced to handle file
attachments to other entities. Attachments store meta data about the
file. The file upload is not yet implemented. It is planned to abstract
the storage handling to allow the support for different storage
solutions (local file system, database, cloud).

Limit logging for profile handling to WARN level for privacy reasons.

Paul-Christian Volkmer authored 7 years ago and Daniel Gerhardt committed 6 years ago

Cherry-picked from GH-52.

Java's ScriptEnging is used to transform design doc JS objects into
valid JSON. A custom CouchDbConnector has been implemented to handle
this transformation and create the design docs in the database at
startup.

Functions need to be stringified to create valid JSON which is accepted
by CouchDB.

Daniel Gerhardt authored 7 years ago and Daniel Gerhardt committed 7 years ago

This eliminates issues in edge cases like calling annotated methods from
inside the same class. The use of `AopContext.currentProxy()` and the
`exposeProxy` setting are no longer necessary for these cases.

The cleanup is now disabled by default and can be set up by uncommenting
the configuration parameter `session.guest-session.cleanup-days`.