[svn] Add SpellExtraInfoMap. Currently support:

Limited-number-of-players spell; shared damage spell; target-in-line cone spell (e.g. dark glare).
Change angle of cone spells from 120 degree to 60 degree.

--HG--
branch : trunk

src/game/Unit.h

@@ -1095,6 +1095,7 @@ class TRINITY_DLL_SPEC Unit : public WorldObject
         bool isInFront(Unit const* target,float distance, float arc = M_PI) const;
         void SetInFront(Unit const* target);
         bool isInBack(Unit const* target, float distance, float arc = M_PI) const;
+        bool isInLine(Unit const* target, float distance) const;
 
         // Visibility system
         UnitVisibility GetVisibility() const { return m_Visibility; }