{dix/,hw/nxagent/NX}dixfont.{c,h}: Support using builtin-fonts. Makes dependency on X11's misc fonts package obsolete.

 This backports a mixture of these X.org commits (only focusing
 on SetDefaultFontPath() function):

 commit 03e8bfa1d122f7dea905d48c93cfd54afd991dfd
 Author: Alan Coopersmith <alan.coopersmith@oracle.com>
 Date:   Sat Nov 27 20:09:04 2010 -0800

    Convert existing Xprintf style calls to asprintf style
Signed-off-by: Alan Coopersmith <alan.coopersmith@oracle.com>
Reviewed-by: Jeremy Huddleston <jeremyhu@apple.com>
Reviewed-by: Mikhail Gusarov <dottedmag@dottedmag.net>

 commit 12e46e83733b47d2704e1509960192365102af46
 Author: Tiago Vignatti <tiago.vignatti@nokia.com>
 Date:   Fri Mar 25 22:07:31 2011 +0200

    dix: fix memory leak in SetDefaultFontPath
Signed-off-by: Tiago Vignatti <tiago.vignatti@nokia.com>
Reviewed-by: Nicolas Peninguy <nico@lostgeeks.org>
Reviewed-by: Peter Hutterer <peter.hutterer@who-t.net>

 commit 6592db6bb526f0c43b4c7b55859c629709e039b4
 Author: Mikhail Gusarov <dottedmag@dottedmag.net>
 Date:   Fri Jun 4 16:58:58 2010 +0700

    Get rid of xstrdup when argument is definitely non-NULL

    Replace xstrdup with strdup when either constant string is
    being duplicated or argument is guarded by conditionals and
    obviously can't be NULL
Signed-off-by: Mikhail Gusarov <dottedmag@dottedmag.net>
Reviewed-by: Alan Coopersmith <alan.coopersmith@oracle.com>

 commit f56cbe1ef24415d0142b9a7d0ab0a031069ccb52
 Author: Rémi Cardona <remi@gentoo.org>
 Date:   Mon Sep 14 17:09:59 2009 +0200

    dix: append "built-ins" to the font path in SetDefaultFontPath

    49b93df8a3002db7196aa3fc1fd8dca1c12a55d6 made the hard dependency on
    a "fixed" font go away but only Xorg could use the built-ins fonts by
    default.

    With this commit, all DDXs get "built-ins" appended to their FontPath, not
    just Xorg.

    Tested with Xorg, Xvfb and Xnest.
Signed-off-by: Rémi Cardona <remi@gentoo.org>
Signed-off-by: Jon TURNEY <jon.turney@dronecode.org.uk>
Tested-by: Jon TURNEY <jon.turney@dronecode.org.uk>
Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

 commit 49b93df8a3002db7196aa3fc1fd8dca1c12a55d6
 Author: Paulo Cesar Pereira de Andrade <pcpa@mandriva.com.br>
 Date:   Wed Jan 7 19:37:03 2009 -0200

    Default to use standard bitmap fonts, with builtins as fallback

      The builtin-fonts configure option was removed, as it at best should
    have been a runtime option. Instead, now it always register all "font
    path element" backends, and adds built-ins fonts at the end of the
    default font path.
      This should be a more reasonable solution, to "correct" the most
    common Xorg FAQ (could not open default font 'fixed'), and also don't
    break by default applications that use only the standard/historical
    X Font rendering.
Backported-to-NX-by: Mike Gabriel <mike.gabriel@das-netzwerkteam.de>

 Fixes ArcticaProject/nx-libs#84.
 Fixes ArcticaProject/nx-libs#285.