Changes to resource node capture

Breaks fog of war code
Fix resource node rendering
Resource nodes give los drawing
Fog of war now obscures units

Changes to how mapDrawer renders, has two lists of things to draw one
list is always visible the other relies on player los. Map is divided up
into tiles, if you have a unit within los distance of the centre of a
tile you can see that tile and everything in it.
Exctract capture distance to constant