block: add transactional properties

block: add transactional properties

Add both transactional properties to the QMP transactional interface,
and add the BlockJobTxn that we create as a result of the err-cancel
property to the BlkActionState structure.

[split up from a patch originally by Stefan and Fam. --js]
Signed-off-by: Stefan Hajnoczi <[email protected]>
Signed-off-by: Fam Zheng <[email protected]>
Signed-off-by: John Snow <[email protected]>
Signed-off-by: John Snow <[email protected]>
Message-id: 1446765200[email protected]
Signed-off-by: Stefan Hajnoczi <[email protected]>
Signed-off-by: Kevin Wolf <[email protected]>