Balance turrets

[ArthurGW]

Just a list of small things that could be improved with the turrets.

• The balance between the plasma cannon and MG felt a bit off. Maybe increase the plasma damage or fire rate?
• Shield booster turret maybe doesn't add much as not many buildings get destroyed. Not sure how to improve that
• Possibly increase ranges on some/all of them, so you don't need to place one everywhere
• Especially true for attack booster for which there's only a few good slots, and it's total boost given is often less than the benefit of just building an attack turret there
• Hover popups currently mention which level they are - either remove that or add an upgrade system

[GavRobbs]

I removed the shield booster in favour of a nano reparator that undoes building damage. I think the ranges are fine, the idea is that you have to decide if you want to put an attack turret or a booster. I do agree that I can increase the effect of the attack booster though.

The plasma cannon fires slowly but now does 50% extra damage against tanks and 100% extra damage against mechs. That should help bring things into balance.

Closing this one.