Heres the latest version of the order system patch I started on with the FIFO thread.
These are the options now available with this patch:

You can load a train to a minimum of 10%, 20%, 30%.... instead of just a full load.
To use this use the new up/down arrows on the orders menu.

Percentile loading is only a guide to when to stop, if more exists it will continue loading. If however you want to force the train to stop loading when the perceile has been hit, use the Exact loading option.
-- use the blank button next to the arrows

Prioritity loading is used to allow some trains to override already loading trains. (eg. a smaller train can take prioritiy over a mammoth train, so money keeps flowing) there are two available ways to use this, the default is to have all NON prioritity trains to load in the normal way (without FIFO) prioirty trains will load using the FIFO method.
The other method is to enable in patch menu option (under Stations) the ablity for all trains to use FIFO/Improved loading, prioritiy trains will always load before a normal train (even if it arrives after a normal train), normal trains will then also FIFO if no prioritiy trains are in the station.

The loading method has been converted from the original HackyKid/Tron improved loading system to be real First In First Out (FIFO) loading.

The amount of cargo is now shown on the 'Loading/Unloading', ';Heading for xxx' status bar. So in the corner you can quickly see how loaded a train is.
Started, but not in GUIs:
* Min and Max waiting times (Just needs GUI and testing)
* Ablity to choose if the full load is based on cargo or train (per queue item, not globally) (Just needs GUI and testing)
* Expand size of orders window based on patch setting (this will be hard)
-- this is currently set at 10 instead of 6... needs a way to be more dynamic.
Still Todo/Thoughts:
* Move the FIFO ablity to the station gui
* Add default order options for station (eg. clicking goto on a station will use the default options for that station)
* Prioritity trains given more chances of being allowed to continue first at a signal
* Remove any of the patch options this will add gui items for
* Possibly also a dont stop if no room option. (Im going to need a new window I think)
* Leave if another X trains are at the station.
NOTE: Currently to avoid a save game bump becuase of the order options the above settings are not saved (sorry). Some of the options will automatically start working (eg. once a train arrives at a station it will start to FIFO. -- If a train was already at the station when loading it will be treated as a lod any situation until it arrives at another station)
Please feel free to apply this patch and let me know of any bugs you find (or even suggestions for the above list)
