[Feature request] Autohide panels only when tiling or maximized

[git-f0x]

This would improve the workflow with floating windows, while preserving space when using tiling or a window is maximized. Currently the panel hides when the first window is opened. This could also be a different setting, if preventing burn-in on OLED displays is a concern (though the current setting should then probably be changed to always hide, regardless of whether a window is open).