Mines should have an impact onto close by agents

[DivineThreepwood]

Once a mine explode it should as well has a impact onto close by agents within a specific radius.

• The maximum damage should not be more that 25 % for nearby agents.
• The damage should depend on the distance between the agent and the mine.
• We need to make sure once the Agent shifting #9 feature is implemented that a shift can help agents to avoid damage for the one that has planted the mine.