Fix buffer pool race condition, pixman transform, and pixel conversion

Mark reused buffers as busy before returning from nextBuffer (before,
they only got marked busy on init).

Re-attach wl_buffer listener after re-initializing a buffer. This lets
the re-inited buffer still get a released event.

Combine scale and translate matrices with multiply instead of overwriting

Use appendAssumeCapacity for pixel conversion loop (since we already
initialized the list with the correct size).

src/main.zig

@@ -134,10 +134,6 @@ fn registryListener(registry: *wl.Registry, event: wl.Registry.Event, globals: *
     }
 }
 
-pub const std_options = std.Options{
-    .log_level = .debug,
-};
-
 const std = @import("std");
 const mem = std.mem;
 const fatal = std.process.fatal;