Building graphviz-2.12.nb1 fails when attempting to apply patch-af, asking for
which file to patch.  The problem is that .../gv_lua.cpp does not exist at
patch time.  It is generated on the fly by swig during the graphviz build.

It looks to me that the proper place(s) for a similar patch is to swig files
.../Lib/lua/luarun.swg and .../Source/CParse/parser.c (appears to work fine
here, but I may not be exercising the relevant features of graphviz to test
properly; someone else should check this, as well).

Mark