a tiling window manager for X11

Changes for 3.0 - 2023-12-07

• Moved to X11::XCB 0.22
• Significantly improved logic around floating windows on multiple screens
• Implemented FocusIn support for background windows: now browser windows steals focus on URL opens.
• Implemented whitelist of windows with unset WM_CLASS: previously we just ignored them.
• Implemented autostart commands in API format (see configuration example).
• Other minor improvements: