Current state of libopencad

Hello devs,

I just have started writing handling functions for all the CAD objects, just like "Layer control" object, and others. It will help to implement writing function to the library, and to understand DWG internal structure way better.

Now, library can work with a big files (tested on 13600 geometries), but it has a few limitations - not all the returned geometries are actually drawn , because DWG stores some info about deleted objects. The only way to handle it - is to compare each object connection to one of the layers, which will be added soon.

Now supported geometries without problems:

- Line, Point, LWPolyline, Circle, Ellipse, Arc (LWPolyline with 'arced' lines also works), Text.

Best regards,

Alexandr.