[Stratagus-ccl] CCL Alteration: minimap (in define-ui)

[Martin Renold]

- 'minimap-panel and 'minimap-pos were compacted into 'minimap
- minimap size is configurable (was hardcoded to 128x128 before)
- new optional tag 'transparent will stop blacking unexplored areas

New docu:

There is a minimap panel an the minimap on it. The panel graphic has
certain palette restrictions (FIXME: exactly? probably the same as the
tileset?). Pos is the absoloute position of the minimap on the screen
(the upper left corner of it). If you give 'transparent, the panel
graphic will be displayed on unexplored terrain, black otherwise.

    'minimap (list
      'file (string-append "graphics/ui/" race "/minimap.png")
      'panel-pos (list minimapx minimapy)
      'pos (list (+ minimapx 27) (+ minimapy 13))
      'size '(128 128)
      'transparent)