Update docs to note a size value of zero may have been set explicitly.

Update docs to note a size value of zero may have been set explicitly.

2006-05-11  Behdad Esfahbod  <behdad@gnome.org>

        * pango/fonts.c (pango_font_description_set_size): Update docs to note
        a size value of zero may have been set explicitly.

        * pango/pango-context.c (pango_context_load_font): Don't warn if font
        size if zero.

        * pango/pangoatsui-fontmap.c (pango_atsui_font_map_load_font):
        * pango/pangox-fontmap.c (pango_x_font_map_load_font): Don't return if
        size is zero (probably will fail with no fonts found.)

        * pango/pangoxft-fontmap.c (pango_xft_font_map_default_substitute):
        * Xft
        chokes on size zero.  Reassing PIXEL_SIZE to 1.0 if it's zero.