- Renamed themes:
- "colorful" to "default" and "colorful_dark" to "default_dark"
- "default" to "monochrome" and "default_dark" to "monochrome_dark"
- "colorful_midnight_blue" to "qdarkstyle_midnight_blue"
- "qdarkstyle_midnight_blue" to "qdarkstyle_midnight_blue_monochrome"
- qdarkstyle is renamed from "Dark" to "Mine Shaft" in the UI
- default and monochrome themes all use the same qss stylesheet
- Remove the ability to select "default_dark" directly
- Add "qdarkstyle_monochrome" theme
- Remove duplicated icon files