Moved all generic CFA-functions into a new abstract class Generic_CFA_PixBuf and derived the ImageFileDirectory from this new base class
Created a new class (derived from Generic_CFA_PixBuf) that contains one frame of a RAW file
Added a function to write a RAW frame back to the RAW file
Fixed missing javadoc
Refactored a test case to use the new method names of Generic_CFA_PixBuf
Added a few convenience functions and fixed an error which occurred when reading or writing raw frames