Added GetArray* wrappers to Gamma.inc

Added GetArrayGameMode to get a game mode from an ADT array
Added GetArrayBehaviourType to get a behaviour type from an ADT array
Added GetArrayBehaviour to get a behaviour from an ADT array
Changed game-mode_template to reflect those additions
Added native Gamma_GetBehaviourFullName

Added native Gamma_GetBehaviourFullName