Don't link libXft when using cairo
* configure.ac: Check cairo early. Don't try Xft if cairo is used. * lwlib/lwlib-utils.h [USE_CAIRO]: Include cairo.h and fontconfig.h. (XftFont, XftDraw, XftColor, XGlyphInfo) [USE_CAIRO]: New typedefs. (XftFontOpenName, XftFontClose, XftDrawCreate, XftDrawDestroy) (XftDrawRect, XftDrawStringUtf8, XftTextExtentsUtf8) [USE_CAIRO]: New macros. (crxft_font_open_name, crxft_font_close, crxft_draw_create) (crxft_draw_rect, crxft_draw_string, crxft_text_extents) [USE_CAIRO]: New externs. * lwlib/lwlib-utils.c [USE_CAIRO]: Include math.h, cairo-ft.h, and cairo-xlib.h. (crxft_font_open_name, crxft_font_close, crxft_draw_create) (crxft_set_source_color, crxft_draw_rect, crxft_draw_string) (crxft_text_extents) [USE_CAIRO]: New Xft compatibility functions. * lwlib/xlwmenuP.h [USE_CAIRO]: Include lwlib-utils.h. * lwlib/xlwmenu.c (display_menu_item) [USE_CAIRO]: Call cairo_surface_mark_dirty and cairo_surface_flush. * lwlib/lwlib-Xaw.c [USE_CAIRO]: Include stdlib.h and lwlib-utils.h. (draw_text) [USE_CAIRO]: Call cairo_surface_flush. * src/xsettings.c [USE_CAIRO]: Include fontconfig.h (apply_xft_settings) [!HAVE_XFT]: Don't call XftDefaultSubstitute or XftDefaultSet. * lwlib/lwlib-Xaw.c: * lwlib/lwlib-int.h: * lwlib/xlwmenu.c: * lwlib/xlwmenuP.h: * src/xrdb.c: * src/xsettings.c: * src/xterm.c: Replace all #ifdef HAVE_XFT with #if defined USE_CAIRO || defined HAVE_XFT. * src/xfns.c (x_default_font_parameter): Replace #ifdef HAVE_XFT with #if defined USE_CAIRO || defined HAVE_XFT.