NSEntity: add method IsFacing() which should make some common sneakish tasks easier.

src/shared/NSEntity.h

@@ -351,6 +351,9 @@ public:
 		of any entity class that you want to support think functions in.
 		This saves you the effort of writing your own routines and methods. */
 	nonvirtual void HandleThink(void);
+
+	/** Returns either true or false depending on if this entity is facing the entity in question. */
+	nonvirtual bool IsFacing(entity);
 };
 
 #ifdef CLIENT

src/shared/NSEntity.qc

@@ -892,6 +892,13 @@ void NSEntity::HandleThink( void ) {
 	}
 }
 
+bool NSEntity::IsFacing(entity target)
+{
+	vector vecDiff = normalize(target.origin - origin);
+	makevectors(angles);
+	return ((vecDiff * v_forward) > 0 ) ? true : false;
+}
+
 #ifdef CLIENT
 void
 NSEntity_ReadEntity(bool new)