Modified MonoFontFamilyProc callback to filter out "vertical" font names (i.e. those beginning with '@')
See http://tinyurl.com/6ul6rfo for details of vertical fonts.
NOTE: this change not to be included in v5 change log since it was also made in v4.8 maintenance branch and so is in v4 change log before v5's first release.
