Mana curse patch.

  This patch is ready to be aplied to Vanilla angband 2.9.5-alpha

  It adds a new item flag : TR3_MANA_CURSE
replacing the (I hope) unnused flag : TR3_XXX1

  Objects to get this flag should get marked with MANA_CURSE at
edit/object.txt

  When the player is wearing an item with this flag all damage done
to him will be deducted from the player mana points instead of the
hit points, if the damage exceeds the player mana points all remaining
damage will hurt the player hit points as usual.
  Which objects should get this curse (wich may be a blessing under
certain circunstances) is up to the mantainer and users.

TO DO:
  The descriptions given about mana curse by self knowledge and *identify*
should be better (or more artistic).
  Wizard mode commands do not know about this flag.

Luthien
josedura@wanadoo.es