MohannadA
Implemented (with appropriate tests)
	- downloading of images from an input stream
	- isCached method
	- getSampleSize
	- bumpOnDisk
	- getImageDimensions
	- invalidateFileSystemUri (no test)
	- calculateAndSaveImageDetails
	- getImageDimensionsFromDisk
	- getDetailsPrioritizable
	- getBitmapSynchronouslyFromDisk
	- testCalculateAndSaveImageDetails
	- getDecodePrioritizable
	- Discussed progress with Jamie