New features
- Add native support for PlutoSDR [574](https://github.com/jopohl/urh/pull/574)
Bugfixes
- do not add URH to autostart on windows [569](https://github.com/jopohl/urh/pull/569)
- save button was not shown when change on saved signal was undone [571](https://github.com/jopohl/urh/pull/571)
- y scale got falsely reset on save [573](https://github.com/jopohl/urh/pull/573)