Added a "put_in_hand_check" which returns 1 if the item can be equipped in the hand. Replaced the duplicated checks in "put_in_l/r_hand"
Silicons override the check and return 0.
Merge pull request #3568 from Giacom/rip_cyborg_inventory_bugs

Fixes #3565. Added a "put_in_hand_check" which returns 1 if the item can be equipped ...