When a multi-column character would straddle the left window border of
a text box, we have to take the inserted space character into account
when we compute how many characters fit into the rest of the line.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
For multichannel mixer controls, add the channel name to each screen
control.
Also make some other small changes.
Signed-off-by: Clemens Ladisch <clemens@ladisch.de>