v6.14.0

• New demos: rich text (demo-14), images & notes (demo-15); errors fixed in other demos, deprecated chart methods replaced
• Documentation: Russian translation, upgrade guide, ImageStyle and Options pages, rewritten README
• Optimized Writer::_writeCell()
• Fixed Charts\Layout::getXMode() and Charts\Layout::getYMode() - fatal TypeError when adding pie/donut charts
• Fixed RichTextFragment::outXml() - font size set via setSize() was not written