When member joins the group and needs to receive an SST it won't
receive the corresponding menbership view event because the SST
happens after the event and will already include the effects of
all events ordered before it. The view then must be recovered from
the received state.
Minor renames and cleanups.
References codership/wsrep-lib#18
* Count separately fragments certified and fragments stored in
streaming context. Storing the fragment may ultimately fail
due to BF abort even if the fragment was succesfully certified.
Therefore we need to have separate counter for certified fragments
to determine if the transaction is streaming and seqnos of fragments
which have been succesfully stored.
* Provider release is called only after succesful fragment certification
and fragment store.
* Fixed handling of write sets with rollback flag set in apply_write_set()
* Added bootstrap service call to do DBMS side bootstrap operations
during the cluster bootstrap.
* Added last_committed_gtid() to provider interface
* Implemented wait_for_gtid() provider call
* Pass initial position to the server state
