Variable-width default font breaks menu alignment

[fecundf]

My default font is `:family "Lucida Sans"' - variable width. Popup renders menus in variable-width-face-buffers unaligned:

Perhaps there are calls to string length, which should be changed to string width?

In any case I can live with it, it just doesn't look as good as it could.

[syohex]

I think it is impossible to solve this issue without using mono space font, such as `Lucida Sans Typewriter.