Previously, if a client had nofocus == true, it wasn't unminimized if sth tried
to focus it. Also, if this client had the WM_TAKE_FOCUS protocol, the focusing
would fail since it's an error to set the input focus to an unviewable window.
For consistency, this also moves the code that sets a client's minimized
property to false into client_unban() since it doesn't make sense to have a
minimized client unbanned (i.e. visible).
Signed-off-by: Uli Schlachter <psychon@znc.in>
47caab4580