Swish-qr

- Change to ECC HIGH

- New release, with included logo

- New release

- Include missing swish logo

- Center swish logo on png image
- Replace image 'swish-corner.png' with corners drawn by code.
- Update 'swish-logo-png' with a higher resolution image.

Added

- Command line interface for generation of swish qr-code images.

Changed

- Wrong parameter name in function generate_swish_code, 'edit_payee' changed to 'edit_message'.