Registers a Scripted Weapon (SWEP) class manually. When the engine spawns an entity, weapons registered with this function will be created if the class names match.
See also scripted_ents.Register for Scritped Entities (SENTs)
Sub-tables provided in the first argument will not carry over their metatable, and will receive a BaseClass key if the table was merged with the base's. Userdata references, which includes Vectors, Angles, Entities, etc. will not be copied.