Focus on mouse button release, not on click

Submitted by HennR

Assigned to Olivier Fourdan @olivier

When you want to drag and drop files from e.g. thunar to audacious, thunar gets immediately focus before your can drop the files to audacious.

This sucks, but is easy to fix, just give the windows the focus after releasing the mouse button.

Thanks for your great work, and greets from Germany.

HennR