* PidNameXSharingFlavor is used by Outlook 2010 so we have
to store it
* 0x5100 is used although it is not in spec as Sharing Flavour
value when the request is denied from a message where
Request + Invitation was sent.
* Return properly PidNameXSharingCapabilities and PidNameXSharingFlavor
as it is an string representation of a hex number
* Try to guess proper sharing flavour value when it is missing
Save them in extra properties from folder container.
This is required because the client once a request is accepted
or denied sets these two properties and save the message again.
As we cannot modify an IMAP message, we use this utility.
See [MS-OXSHARE] Section 3.1.4.3 for details.
It acts as a proxy of MAPIStoreMailMessage and it manages the properties
defined in [MS-OXSHARE] Section 2.2 by storing them in the mail message
as eXtensible MIME headers which starts with X-MS-Sharing.
Enrique J. Hernández Blasco