Non-attacking towers

[Kvel2D]

Some towers do not attack. This is what they look like in original youtd:

Important points:

• There's no attack section in the selected unit UI. Only "Armor". So the unit doesn't have the "attack" ability at all.
• Base damage is 1 but it doesn't matter because tower won't attack.
• Attack range is 1000, probably to display the range of tower's ability.

Since there's no attack section in original youtd, youtd2 should also not show any attack related stats in unit menu, if tower doesn't attack. This means the following stats:

• Attack range
• Damage
• Attack type
• DPS

[Kvel2D]

This commit removes attack section for non-attacking towers:
9c7fef9

This commit sets non-zero ranges for non-attacking towers:
499a8a5