All the GUI now benefit from the Go Back button to go to the previous inventory without closing the current one.
Make sure to reload your GUI folder in order to benefit from those changes (the corresponding item has the function go-back if you want to customize its look/slot)
Added /contract admin remove <contract-name> command to remove safely a contract & refund the parties that paid money for it. Can be used to remove contracts with "injurious" terms in it.