Batch pacman AI approach

Solution approach for upcoming pacman games GHOST AI's.

clone food sprite list and periodically [each n moves depending on ghost] use rng to select new ghost target tile, trimming list after evaluating the ghost current coordinates and target cells cordinates.
traverse list from position, generate new list when either of the following is true:
  - Ai reaches target tile
  - Pacman is closer to ghost than ghost is to target tile
  - ? Update list when any node is encounterd; Mantain list of nodes
    - ? maintain lists for each ghost with their position relative to pacman and assess string length / value to determine the shorter path.

Food sprite list must fall within batch line limit. Original pacman grid size of 28x 36 cells should support this.


Add refresh.sprite macro to Game_Engine.bat macro to support food trail reset
  - iterate over sprite list and test cell for definition. if not defined, define using sprite list value.
  - output any re-definitions to foreground file, type file.
Expand refresh.sprite macro on food collection.

? Additional Macro's for Game engine Get.Trail Follow.trail
::: [ ? Single Cell Sprites only - may be expanded for multi cell sprites ; though intent is to limit actions for efficiency ]
 - Get.Trail
  - Arguments:
   - Object identity via substring modification
   - Target Cell 0,0
   - Origin Cell 0,0 [ Obj.ly;Obj.lx ]
   - List Varname Containing Full Trail
  - Actions:
   - ? Clone Trail, Trim via substring modification retaining positions between Target Cell and Origin Cell
     - Trim list to consider Relation of Target 0,0 and origin 0,0 and:
      - If Target x/y GTR origin x/y 0,0 remove cells containing x/y values LSS than origin
      - If Target x/y LSS origin x/y 0,0 remove cells containing x/y values GTR than origin
   - Return trimmed trail to obj.path variable
 - Follow.Trail
  - Arguments:
   - Object identity via substring modification
   - Collide / Capture Args
  - Actions:
   - Test next cell in lists definition for collide / capture args, return values if True
   - Move Object to Next cell in list
   - remove cells new location from list
   - Update cells definition with Objects value
   - Undefine and clear cells previous position using Obj.l{X/Y} values
   - Update Obj.lum{X/Y} values