Create: Signalling Additions

1.4.0 is finally fully released

Changes from 0.1.3b

• Added Speed signs, with up to 3 different catagories. These catagories can be assigned to individual trains with the schedual.
• Added Shunt Signal family, 3 main types with 3 variants each, as well as end shunt sign.
• Added Dead End and Shunt add on lamps for mainline signals, and new entries in the GUI for Route Interfaces
• Added Fixed Red Signals for both single and double colour light signals.
• Added Signal Data plate, basically a custom sign to place under signal heads for ID purposes.
• Added 2 Aspect Single Colour light signal
• Added Repeater Signal for limited line of sight
• Optimisation fixes to ensure smoother running.
•