Angels used the epri extension even though they're never priests,
presumeably because they're sometimes flagged as "renegade". Since the
only priests ever flagged as renegade are roaming minions rather than
temple priests, move the renegade flag to the emin extension and switch
Angels over to that. Summoned Angels will now always have the isminion
flag set.
Makefiles need updating: monst.{c,o} now depends upon emin.h.
