Some data updates for the 3rd competition

[domob1812]

This is a set of data and parameter changes for the upcoming competition:

• Character cost is set to 10 CHI.
• Neutral safe zones are placed (fixing #141). They are 30 hexes around each non-ss initial building.
• Some vehicle stats are updated, mainly mining rates.
• Building stats are updated with proper HP and in general combat data.
• The ep and et building types are removed. Energy plants are not in the game (at least for now), and we will only use rt for turrets.