Additions are for my custom game engine.
PO flag - creates physics object with properties.
SO flag - if PO is selected - creates static physics objects - makes easier to build level boundaries.
AO - creates animated object.
FO - unused
Primitives are for farseer physics engine - they are used exactly like original primitives - my engine processes them later.
I just added custom properties.
Revolute joint - in custom properties there are references to physics objects (Body1, Body2) - does not work when objects are copied - maybe someone can fix that.
Angle joint - exactly the same.
Slider Joint - the same.