message: Don't display barbarian only units in tech tree
diff: @@ -245,7 +245,7 @@ class CvTechChooser:
  # Units
  for iClass in xrange(gc.getNumUnitClassInfos()):
  iUnit = utils.getUniqueUnitType(self.iPlayer, iClass)
  - if iUnit > -1:
  + if iUnit > -1 and not gc.getUnitInfo(iUnit).isGraphicalOnly():
  iTech = gc.getUnitInfo(iUnit).getPrereqAndTech()
  if iTech > -1:
  self.TechEffects[iTech].append(("Unit", iUnit))
  