Added Item based economy for offer into the auction
Can be activated from the config by set to true "item-economy"
You can change the item to be offered by changing the material to the config string "item-material-economy"
Fixed the starting auction price that at every start/reload of the server was the default 2000, now it work correctly

NOTE: For change the economy symbol just go into the messages.yml files where you can change the messages
NOTE: the item based economy is in beta so for any bugs contact me on discord or on spigot!
Requested from Netherpwn