CMF2 Modular back with click attachement

Added easy to use modular attachement at the back of the case, which can be used to mount different types of modules. Low tolerances and click holes make sure the phone stays properly attached and won't fall off. Created 3 additional modules for this system. Vent holder for a car, simply push it into the went, and then attach the phone. D ring to be used as additional stability while holding the phone Mount for a bicycle/motorbike handlebars. Will require addiional screws to keep it together