* Accelerate vImage Swift Overlays
A suite of functions, enumerations, and option sets to make working with vImage in Swift simpler.
* vImage_Buffer - new initializers to instantiate and initialize buffers with a single function call.
* vImage_Buffer - new functions to copy buffers and create CGImage instances from contents.
* vImage_CGImageFormat - new initializers.
* vImage_CGImageFormat - new equivalence operator.
* vImageConverter - methods to wrap free functions.
* vImageConverter - new make and convert functions.
* vImageCVImageFormat - new make functions.
* vImageCVImageFormat - methods to wrap free functions.
* vImage_Error - errorDescription function.
* vImage flags as an option set.
* Add new methods for generating CV -> CG and CG -> CV converters.
* update comments: `height` and `width` to `size`.
* `vImage_CGImageFormat.componentCount` should be `Int`.
* `vImage_CGImageFormat.componentCount` should be `Int`
* Move `self.init()` to after the size check for kvImageNoAllocate init.
* Buffer initializers to width and height rather than size.
* change vImage_CGImageFormat lightweight initializer to accept Int for `bitsPerComponent` and `bitsPerPixel`.
* Flesh out docs for vImage_Buffer.size
* Remove faux initializer in favor of new static function: `preferredAlignmentAndRowBytes`.
* Change functions to use proper error handling rather than inout error codes.
* Removed `flags` from basic init.
The only real flag to pass here is print diagnostics to console, and I now throw proper errors.
* Tests to check error throwing for buffer copy.
* remove unnecessary import, add missing docs.
* Add comments to error enums.
* Fix bug creating string from format code.
* Make `vImageCVImageFormat.formatCode` a `UInt32`.
* Remove equivalence operator from `CGImageFormat`.
