Completion suggestions are now nicely formatted into a table.
Maximum width of the table is estimated based on OSD size and
font size.
This requires a new scaling factor option `font_hw_ratio`.
A factor of 2.15 works great for me,
but the default is 2.0 to avoid problems with other fonts.
The space between columns is automatically adjusted to be
between 2 and 8 spaces.
It tries to use as few rows as possible.
Christoph Heinrich
ed8a919812