#noissue: Change the way for retrieving ownCloud dependencies.

Remove ownCloud constants and interface of the current project and add a new dependence "ownCloudInterfaces" with composer for including ownCloud constants and interfaces.
#noissue: Remove phpunit dependency of the project.
Merge branch 'master' into feature/IS-7
IS-7: Add a new control to configurate the authenticator whether we use SSL for authenticating users.
IS-7: Read the SSL settings for building the mailbox string passed to imap_open.