Add a call to replicate pre-ordered actions

https://bugs.launchpad.net/wsrep/+bug/1076469 was a wrong direction.

After sufficient consideration it is now clear that lp:1076469 should be reversed, and instead a call to replicate actions in predefined order must be added.

something like

wsrep_status_t wsrep::replicate_preordered (const void* act, size_t act_size);

or iovec-like interface.

The actions shall be replicated asynchronously and received through wsrep::recv() call and will be assigned wsrep GTID (that will preserve the partial order in which replicate_preordered() was called). As a result, original TID assigned to the action by the original ordering entity must be enclosed into the buffer.

From which follows that unordered actions, replicated through pre_commit() call should contain empty TID to be distinguished from pre-ordered ones.