Made it possible to change the header.
Removed unnecessary(5) constructors.
Major refactor of the constructor that parsed the data, and idenftified it.
Cleaned up the main public Append method.
Cleaned up the main public Prepend method.
Renamed the 'Update' method to 'Reconstruct'.
Reconstruct method will now only update Body, and RawBody when the length has been changed.
Removed 'ProcessAncient' method, it is now handled in 'main' constructor.
Cleaned up non-static 'ToBytes' method.
Cleaned up non-static 'ToString' method.
ConstructAncient/ConstructModern have been merged and replaced by Construct.
Split construct so that ConstructBody will created the 'Body' of the packet, while Construct will take care of the 'dynamic' parts.