Revert change to priority in cea4f90. Set initial pq distance to max().
Revert change to priority in cea4f90. Set initial pq distance to max().

The change in cea4f90 changed the order in which trees where traversed.
Starting with the max we make sure to first find all candidates that
match on the probed bits, then have one bit different, two bits different,
and so on.

eddelbuettel/annoy,tjrileywisc/annoy,eddelbuettel/annoy,tjrileywisc/annoy,spotify/annoy,eddelbuettel/annoy,spotify/annoy,eddelbuettel/annoy,spotify/annoy,spotify/annoy,tjrileywisc/annoy,tjrileywisc/annoy