CIDetector will now only init once.

Core Image Contexts/Detectors should be initted (yes that's made up) as sparsely as possible. The reason being is each time you init one you're using GPU compute and memory. This competes with a things like UIScrollViews which are very GPU intensive.

CIDetector is still very resource hungry and I've only tested this code on an iPad Air for performance where its usable, around 40fps rather than 60fps.
Moved CIDetector as a static implementation
Moved the options inside the if statement.
Changed !detector to !detector == nil
Removed a CIImage recreation via a UIImage's CGImage. Directly create a CIImage off a UIImage
Merge pull request #8 from neoplastic/noCIReinit

CIDetector as a Singleton