Exporters with dirty rectangle

• This version work with dirty rectangle in roassal

First release

• PNG exporter.
• Two SVG exporters, one provided by cairo another provided by
• One PDF exporter
• AFrame exporter, using 3d visualizations.
• Video exporter based on PNG exporter and ffmpeg project. not available in windows os due the lack of support of OSSubprocess the bridge between exporters with ffmpeg.
• Inspector support, users can use a export button in the canvas inspector.
• Collaboration with units to change the canvas size according with paper extent formats (A4, Letter, etc).
• More tests