Commented the pass about internal impls of abstract classes. Cosmetic fixes.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>
Changed the parameter type comparer to work with qualified types because overriding cannot change the qualification of types.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>
Documented the addition of internal implementations to the respective unit.

Signed-off-by: Dimitar Dobrev <dpldobrev@yahoo.com>