Initialized random seed at startup

Set to the current time.
Refactored Filter class

Modified Token struct, added comments, minor refactoring.
Refactored ImageSource class

Modified interface and added default implementations for some functions.
Refactored ImageInfo class

Added documentation and comments, renamed some member functions, removed
some member functions.
Added the Utility class

Including methods to get the supported file types for the application.
Added the LocalImageSource class

Represents a source of image files within a local directory.
Added default argument value to the Filter class's constructor

Defaults to an empty string.
Changed ImageInfo instances from pointers

QList automatically handles non-pointer objects with pointers.
Modified ImageList class's sorting algorithm

Now uses absolute file path rather than just the file name.
Added QuaZipImageSource class

Represents a source of image files within a zipped archived.