Adds lockboxes to mech weapons, excluding clown mech weapons

Anything of type or subtype /obj/item/mecha_parts/mecha_equipment/weapon is built in a lockbox that requires security access (or an emag) to unlock.  Exception being clown mech gear.  
Tested and confirmed to compile and have desired effect.  
Whitespace changes made by Dream Maker for unknown reason, but do not appear to do anything.