Adds in 2-combo sight. Ironsight and Digital Tracker sight
Digital tracker sight have more zoom and highlight special enemies.
Sight can only be used on M4 for now
(It's hell making it compatible on other weapon, so if there's high demand for the sight on other weapon, I'll update it)
Thanks to Cpone for providing the gadget_linking function on EATD for this sight to work
Thanks to Offyerrocker for fixing flashlight issue on gadget combo, with the sight (not yet implemented)