Fix guns and cuffs

Fixes guns by adding in the other two parts of the attack chain which were accidentally left out of preAttack() (```attackby()``` and ```afterattack()```). This re-enables them to shoot on help intent and interact with objects such as backpacks and tables.
Also fixes handcuffs by adding the ```restrained()``` check to ClickOn() (also accidentally left out).

Obviously non auto-mergeable atm, but made this anyway since I'm not sure how else to submit fixes to reverted changes.