Include <fontconfig/fcfreetype.h> if HAVE_XFT2.

Include <fontconfig/fcfreetype.h> if HAVE_XFT2.
(MXFont): This type deleted.
(MFontX): New type.
(struct _MFontX): New struct.
(SET_SIZE, HAVE_SIZE): Adjusted for the change of arg FONTX.
(MDisplayInfo): Member base_font_list deleted.
(DEFAULT_FONT): Definition changed.
(FALLBACK_FONT): This maclr deleted.
(free_display_info): Adjusted for the change of MDisplayInfo.
(free_device): Argument to mfont__free_realized changed.
(xfont_driver): Adjusted for the change of MFontDriver.
(xfont_registry_list): Use MFontX instead of MXFont.
(MRealizedFontX): Renamed from MXFontInfo.
(xfont_select): Return the font found first.
(close_xfont): Change MXFontInfo to MRealizedFontX.
(xfont_open): Return the realized font.
(xfont_find_metric): Get xfont from rfont->fontp.
(xfont_has_char): New function.
(xfont_encode_char): Adjusted for the argument change.
(xfont_render): Get xfont from rfont->fontp.
(xfont_list): Adjusted for the argument change.
(MRealizedFontXft): Renamed from MXftFontInfo.
(xft_driver): Ajusted for the change of MFontDriver.
(close_xft): Change MXtfFontInfo to MRealizedFontXft
(xft_open_font): Argument changed.
(xft_open): Argument changed.  Return the realized font.
(xft_find_metric): Get xft_font from rfont->fontp.
(xft_has_char, xft_encode_char): New functions.
(xft_render): Change MXftFontInfo to MRealizedFontXft.  Open a
font if not yet opened.
(device_open): Don't set frame->font.