suggestion - buy/sell all option

[pahanakun]

It would be handy if when right clicking on a sign, it gave you the option to buy or sell all in your inventory or the chest. Other chest/sign shop plugins/mods have this feature, and it would be awesome if GunpowderSignshop could have it as well.

Its fairly limited right now, afaik you can only buy/sell up to a max of 64. So if for example someone had an inventory full of stone that they wanted to sell, they'd have to click the sign and then click confirm 27 times.