1、most of the concrete fortifications have been reworked, concrete mg&at bunker tower and fortress.
2、straight trench is now draggable.
3、new fortification：concrete wall, taller than standard barricade wall,and it also has an embrasure allowing infantry to fire throght it.
4、fixed some weapons that don't spawn or upgrade properly.

all factions are now able to build concrete fortress with their heavy shovels.