tests: added golden files for an ELLIPSE entity.

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
tests: added golden files for a POINT entity.

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
tests: added golden files for a POLYLINE (rectangle shape) entity

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
SEQEND: additions.added members to the DxfSeqend struct.

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
SPLINE: added spline.[ch].

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
SPLINE: added dxf_spline_new().

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
SPLINE: added dxf_spline_init().

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
SPLINE: added dxf_spline_free().

Signed-off-by: Bert Timmerman <bert.timmerman@xs4all.nl>
Merge remote branch 'bertmaster/master'
Documentation: added DXF binary description