Log Message:
Update luatex to 0.76.0.

Changes since 0.70.1:
    * Metapost 1.801.
    * Small patches from TeXLive 2013, as well as an update to the
      latest libraries (libpng, poppler, etc.)
    * Speed up printing (of TeX strings) to the terminal and log.
    * New lua function node.end_of_math().
    * Fixed a memory leak in the lua function pdfscanner.scan().
    * New expandable primitive \Uchar.
    * New version of lnodelib.c with speedups by Hans and Luigi.
      Also added some extra sanity checks to the Lua node field
      setting functions.
    * Support 'umath' in tex.extraprimitives(), so that formats can
      make the \Umath* primitives unprefixed, now that they will be
      provided by XeTeX as well.
    * Removed a bunch of deprecated primitives
      * \AlephVersion, \Alephrevision, \Alephversion, \Alephminorversion
      * \OmegaVersion, \Omegarevision, \Omegaversion, \Omegaminorversion
      * \omathcode, \odelcode, \omathchardef, \omathchar, \omathaccent,
        \odelimiter, \oradical
      * \Umathbotaccent, \Umathaccents
    * Fix large file support.
    * Fix Lua's loadfile().
    * Removed the cidmap callbacks again (let that be done by user lua
      code after the fact).
    * Removed the fatal error on fonts where num_glyphs is too high,
      as that problem is actually harmless.
    * Some compilation issues under Win32 and Solaris resolved.
    * Allow math extender objects to be zero width.
    * The 'epdf' library has been extended to deal with finding and
      saving embedded files (catalog:numEmbeddedFiles() and catalog:
      embeddedFile, new EmbFile object).
    * lua 5.2
      There are no patches to the core Lua files; a future version
      of luatex will switch to loading the regular lua 5.2 dynamic
      library instead of depending on a statically compiled
      one.
    * A bleeding-edge version of luasocket is included, as there
      is no 5.2-compatible official release yet.
    * A new lua extension is the two-argument version of
      string.dump from Luajit.
    * Two new callbacks: find_cidmap_file and load_cidmap_file
    * update various used libraries.
    * new 'pdfscanner' lua library.
    * various OpenType math fixes, including \Umathcharnumdef.
    * improved placement of bottom accents.
    * various other small fixes.