(Qmonospace, Qsans_serif, Qserif, Qmono, Qsans)

(Qmonospace, Qsans_serif, Qserif, Qmono, Qsans)
(Qsans__serif): New variables.
(ftfont_generic_family_list): New variable.
(syms_of_ftfont): Initialize the above variables.
(ftfont_pattern_entity): Argument NAME deleted.
(ftfont_list_generic_family): New function.
(ftfont_parse_name): Delete this function.
(ftfont_list): Try generic family only when FcFontList found no
font.
(ftfont_list_family): Fix args to FcObjectSetBuild.