(QCscalable, Qc, Qm, Qp, Qd): New variables.

(QCscalable, Qc, Qm, Qp, Qd): New variables.
(syms_of_font): Initialize them.
(font_pixel_size): Allow float value in dpi.
(font_prop_validate_type): Deleted.
(font_prop_validate_symbol, font_prop_validate_style): Argument
changed.  Caller changed.
(font_prop_validate_non_neg): Renamed from
font_prop_validate_size.
(font_prop_validate_extra): Deleted.
(font_prop_validate_spacing): New function.
(font_property_table): Add elements for all known properties.
(get_font_prop_index): Renamed from check_font_prop_name.  New
argument FROM.  Caller changed.
(font_prop_validate): Validate all known properties.
(font_put_extra): Argument force deleted.  Caller changed.
(font_expand_wildcards): Make it static.  Fix the way of shrinking
the possible range.
(font_parse_xlfd): Arguemnt merge deleted.  Fix handling of RESX,
RESY, SPACING, and AVGWIDTH.  Don't validate property values here.
Caller changed.
(font_unparse_xlfd): Handle dpi, spacing, and scalable properties.
(font_parse_fcname): Arguemnt merge deleted.  Fix parsing of point
size.  Don't validate properties values here.  Caller changed.
(font_unparse_fcname): Handle dpi, spacing, and scalable
properties.
(font_open_by_name): Delete unused variable.
(Ffont_spec): Likewise.  Validate property values.
(Ffont_match_p): New function.