- Add support for SIDEBAR_ICONS on macOS
- Allow specifying a basename for the icon file via OUTFILE_BASENAME
- Add support for HiRes icons on Windows via icotool
I'm sorry this went all into one big change. I see that it's not optimal,
but it's really hard to rip it apart...
Also to me the whole code with support for two flavors of png2ico and icotool seems very spaghetti-ish. IMHO there's no good reason to keep supporting all three, icotool is the only maintained project and the only one supporting more than 128px wide icons. That's why I would suggest to simplify the whole code by only supporting icotool in one of the next releases.