Melee units with big maximum range can attack through walls

[sanderd17]

There are a lot of melee units that can attack throug the Roman siege wall, and even more that can attack through pallisades.

The melee unit with the biggest range (the Spartan champion pikeman) can even attack through the spartan stone wall.

I don't know how to solve this. Maybe add a check if there is an obstruction between the two parties, and don't execute melee attacks if there is an obstruction (units shouldn't even preform the attack animation when there's an obstruction).