TCS extensions

Two additions will be made in the SignalFeatures struct:
- In addition to the main head signal type name, the struct will also contain the name of the signal type for the current head (which will be different for the other heads of the signal).
- In addition to the aspect of the signal, the name of the draw state will also be included.

Also, a SetMaxThrottlePercent function will be created to set a max throttle percentage. This will be used to reduce the throttle before open the circuit breaker when crossing a neutral section.

Discussions : http://www.elvastower.com/forums/index.php?/topic/33693-expand-potential-of-tcs-scripting/page__view__findpost__p__277490