Bulk Fill

Any refillable tools (seeders, sprayers or trailers) can now 'Bulk Fill' from multiple pallets or big-bags using only a single fill command, as long as there is another matching fill unit in range.

Features:
- Bulk Fill allows continuous filling from multiple pallets or big-bags
- Ability can be toggled using the 'Insert' key, in case you need to load a single pallet
- Toggled state is stored independently for each tool when saving the game
- The fill levels and order of the available fill sources are displayed
- It is also possible to select the first item from which to begin filling
- Covers will open automatically on tools such as seeders with fertiliser tanks