CamelCipherContext: Remove all asynchronous class methods.

For consistency with CamelStore, CamelFolder, etc.
CamelDataWrapper: Remove all asynchronous class methods.

For consistency with CamelStore, CamelFolder, etc.
CamelMimePart: Remove all asynchronous class methods.

For consistency with CamelStore, CamelFolder, etc.
CamelOfflineFolder: Remove all asynchronous class methods.

For consistency with CamelStore, CamelFolder, etc.
CamelSasl: Remove all asynchronous class methods.

For consistency with CamelStore, CamelFolder, etc.
CamelSession: Remove all asynchronous class methods.

For consistency with CamelStore, CamelFolder, etc.
CamelCipherContext: Port to GTask.
CamelDataWrapper: Port to GTask.
CamelFolder: Port to GTask.
CamelMimePart: Port to GTask.
CamelNetworkService: Port to GTask.
CamelOfflineFolder: Port to GTask.
CamelSasl: Port to GTask.
CamelService: Port to GTask.
CamelSession: Port to GTask.
CamelStore: Port to GTask.
CamelSubscribable: Port to GTask.
CamelTransport: Port to GTask.