Edited the description of hook/functions in the previous commit

Rewrote ASM code for tile_under_cursor script function.

artifacts/scripting/hookscripts.txt

@@ -653,10 +653,11 @@ int     ret1 - pass -1 to cancel the execution of the handler (only for HOOK_STD
 
 HOOK_TARGETOBJECT (hs_targetobject.int)
 
-Runs whenever the targeting cursor hovers over something.
+Runs when the targeting cursor moves over an object, or when the player tries to attack the target object.
+You can override the target object or prevent the player from attacking the chosen target.
 
-int     arg1 - event type: 0 - when hovering over the target, 1 - when clicking on the target
-int     arg2 - 1 if the target is a valid object, 0 otherwise
+int     arg1 - event type: 0 - when the cursor moves over the object, 1 - when trying to attack the target object
+int     arg2 - 1 when the target object is valid to attack, 0 otherwise
 Obj     arg3 - the target object
 
-int     ret1 - overrides the target object
+mixed   ret1 - overrides the target object, or pass -1 to prevent the player from attacking the object