Rename attacker to gatherer and defender to hunter

[JonnyBoi-13]

Fixes: #75

[otizonaizit]

Finally someone tried this! I vote for merging this and testing it in Plovdiv. If people are more confused, we switch back to attacker-defender.

[Debilski]

Yeah, it solves the ambiguity for the gatherer at least. I think there is still a small mental mismatch (for me at least) with a hunter that does not attack but just defends its base. But we’ll see. I guess ‘gatherer and defender’ isn’t really a naming option here. :)
Thanks for submitting, we will try it out.

[Debilski]

A basic hunter bot implies the existence of an acidic gatherer bot. :)