Editing a GenericMaterial works with new classes

This doesn't bring anything new from the existing functionality,
but allows integration of DisneyMaterialEditor.
Editing a DisneyMaterial is impossible since it is impossible to
create one. The editor window exists but is empty for now.

Signed-off-by: Marius Avram <marius.avram1309@gmail.com>
Removed trailing whitespaces

Signed-off-by: Marius Avram <marius.avram1309@gmail.com>
Dummy forms

Signed-off-by: Marius Avram <marius.avram1309@gmail.com>