Adds Monadnock PR-24 Control Baton

The Monadnock PR-24 replaces the generic tonfas used by law enforcement officers. A high-end, collapsible, lightweight, side-handle police baton, this is the gold standard for officer safety and effective crowd control.

This PR also replaces the shock tonfas in the cop_weapons spawn list with actual tazers, which they did not have before and would likely use instead of a cobbled-together amalgam of 3 different tools.
Monadnock themselves: http://www.batons.com/media/default/brochures/brochure_PR-24.pdf
Say the PR-24 is 680-880g, you're talking about "control device 24", which seems to be billed as being less about hitting people and more about putting them in arm locks.
I have no idea which of these is the more typical model, so go ahead and pick one, but if the weight is lower the bash damage needs to drop as well.  In addition to being an easier carry, lower weight means faster swings, so it unduly increases the DPS.
Personally I think a collapsible baton is enough distinctiveness on its own, so I'm fine with either same overall stats and collapsible, or lighter and lower damage.