per: Add the No_Diplomacy effect, which stops a play...

This is an automated notification of a change to freeciv cvs, 
on Mon Aug 22 14:15:48 PDT 2005 = Mon Aug 22 21:15:48 2005 (GMT)
by  <[email protected]>

---- Files affected:

freeciv/common player.c effects.c effects.h unit.c
freeciv/server diplhand.c diplomats.c plrhand.c
freeciv/data/default effects.ruleset
freeciv/ai aicity.c

---- Log message:
      Tag: HEAD

Add the No_Diplomacy effect, which stops a player from having any diplomactic relations 
to any other player, including embassy actions by diplomats and spies.

This is meant to replace some checks for is_barbarian() by something more
generally useful. See PR#13716.