Add new power repair

Repair your RPGitem (or reload it) with repair power
/rpgitem your_item power repair <durability> <[Material|hand]> <display> <click[left|right]> <sneak[true|false] >

durability: durability gain per repair item
material/hand: item to repair the RPGitem, use hand to set the custom item in your main hand
display: display text on the tooltip
click: right or left to repair
sneak: whether sneak while clicking to repair the item