Hideable contracts — Distributrains Steam update #1620551

Contracts can now be hidden from tabs by right-clicking them The incomplete contracts tab now longer shows contracts that do not require the player to do anything Dragging vehicles into the top row at the train core will now set the build row to the top row if none was selected Improved the behaviour of turntable and train core train lists when the list is being modified while dragging Increased maximum output of nuclear power plant Added more informative error output on some error conditions when joining a multiplayer game