Merge pull request #750 from owncloud/unified-inbox

appinfo/application.php

css/mail.css

js/mail.js

js/views/sendmail.js

lib/account.php

lib/controller/accountscontroller.php

lib/controller/folderscontroller.php

lib/controller/messagescontroller.php

lib/mailbox.php

lib/message.php

lib/service/accountservice.php

lib/service/iaccount.php

lib/service/imailbox.php

lib/service/unifiedaccount.php

lib/service/unifiedmailbox.php

templates/index.php