Log Message:
Update luatex to 0.40.6.

Changes since 0.40.2:
        * Fix two string vs. toks bugs in the lua node interface:
          whatsit,annot and whatsit,startlink data assignments were
          made directly as strings instead of being converted to tokens.
        * Sometimes pdf.print() could be used before the proper structures
          were initialized.
        * There was a bug in the type codes for the lua package filter
          callback: wrong extra info was passed to lua for the alignment
          and vsplit cases.
        * The math parameters \Umathlimitdownvgap, \Umathlimitdownbgap,
          and \Umathlimitdownkern have been renamed to \Umathlimitbelowbgap,
          \Umathlimitbelowvgap, and \Umathlimitbelowkern to be more
          consistent with the other parameter names.
        * The embedded MPlib is now 1.204.
        * Handling of UTF-8 hyphenation exceptions has been fixed.
        * There were a number of typos in the manual.
        * One of the internal print functions accidentally encoded its
          argument string to UTF-8 even though it was already UTF-8.
        * Some of the log and terminal UTF-8 output was gibberish.
        * \the\textfont0 returned a number instead of doing a font
          switch.
        * A set of portability fixes for the AIX compiler from Vladimir
          Volovich.
        * A set of fixes to the synctex support.
        * A patch to the build script to prevent installed X11 headers
          from being required.
        * Some weave (web syntax) fixes from Manuel Pégourié-Gonnard.
        * A simplification in luatex.ch (it is now less verbose
          about the web2c-specific extensions) from Karl Berry.
        * A fix in the handling of UTF-8 (input) file names.
        * Hyphenation exceptions were case sensitive in 0.40.2.