New features:
- Download PDF files as well and provide them offline
- Added sharing button and menu:
- Open PDF: Open the PDF on the device with the default app for PDFs
- Share PDF: Via the platform's share dialog
- Open in browser: Open the current worksheet on https://www.4training.net in the browser
- Share link: Share the link to the current worksheet on https://www.4training.net via the platform's share dialog