* Yakifo/amqtt#261 : plugin for authenticating a user with ldap.
* adding openldap dependencies
* updating ldap custom schema to include three ACL attributes, retrieve the correct topic list and check if topic is allowed
* states, calculations and model for shadow plugin
* adding tests for shadow states and correcting use cases
* adding get/update message broadcast, adding json schema tests for shadow messages being received
* adding shadow plugin documentation
* plugin for authenticating clients based on certificates
* create ca, server and device keys and certificates. certificate auth plugin verification (non linted)
* adding documentation for the various cli scripts and the CertificateAuthPlugin
* post_init was not running on client config. cafile, keyfile, certfile are part of the connection section
* 'broker' section of client config can be empty, but connection will either be provided by the user or the default
* rebuild of the persistence plugin to handle storing / restoring sessions
* adding event for broker when a message is being retained
* adding retained message logic to persistence plugin and test cases
* updated documentation
* moving DataClassListJson field to common location for reuse
Andrew Mirsky