added a 1d depth buffer
Gave players a circular 1d depth buffer and made a los shader.
Guard against NaNs showing up in mana regeneration
Guard against what I think is a bug in ManaSource.getPlayerRanges().

If there is an obstacle that touches the leftmost edge of the board it
will prevent playerThinkData.minY from being set properly.  This causes
an index out of bounds exception later on.
Render lava properly when there is more than one polygon of it
los shader properly handles variable numbers of players now
Made a more interesting basic level and made it render better