O365

Features:
- Message now recognizes EventMessages: an EventMessage can retrieve the related Event
- Added isReadReceiptRequested and isDeliveryReceiptRequested to Messag

Features:
- Message can now handle flags
- ApiComponent now stores the logic to convert to/from dateTimeTimeZone resource

Features:
- Connection: add tenant_id parameter
- Mailbox: Folder allows to get a message by id ('get_message').
- Message: constructor now accepts a object_id parameter
- Message: new method 'save_message' now allows to save draft-independent properties of a message: is_read and categories for the moment.

Features:
- Added Token Backends: Now tokens can be stored anywhere with a concise api
- TokenBackends available: FileSystemTokenBackend and FirestoreTokenBackend
- Token dict: tokens expose new properties like: "expiration_datetime", "is_expired" and "is_long_lived"
- Account: New property "account.is_authenticated": Checks if the token exists and if it is expired
- Connection: The "refresh_token" method now detects if the token can indeed be refreshed.

Features:
- Bug fixing release

Features:
- Calendar: `get_events` method now includes a new param 'include_recurring' to include all recurring events. Internally will request a calendarView if 'include_recurring' is True (this is the default behaviour).