Further cleanup of the pickup code regarding autowielding and autowearing

Essentially cleaned up two things (both of which were an issue before adding hands-free code):
* auto-wearing things picked up from the ground was dependant on whether you were armed or not
* there was a dead branch in pickup code (apparently it was trying to make use of player::is_suitable_weapon(), but the way the pickup function was written, the code was never triggered. Furthermore, the branch used hardcoded values for volume overload, instead of can_pickupVolume, which factors in stuff like mutations etc.

With these changes, dressing up as a shower victim should be finally as convenient as it could be ;-)
I think the idea is that if your bionic weapon gets in the way of wielding something, it probably also gets in the way of using that hand to do snaps, buttons, zippers, etc. So the NO_UNWIELD check should apply here.