Lua 5.2.3 vanilla, unpatched

The following changes where done to fit the Wolframe build process:

* Makefile has been renamed to 'Makefile.orig'.

* 'GNUmakefile' and 'Makefile.w32' are added for the
  Wolframe project.

* The CFLAGS should be the same as in the original Makefile.

* The define switch for creating DLLs is called 'BUILD_SHARED' in
  Wolframe. We use it in 'luaconf.h' to trigger the correct
  DLL function markers as in:

  #if defined(LUA_BUILD_AS_DLL) || defined(BUILD_SHARED)	/* { */
  
  instead of only

  #if defined(LUA_BUILD_AS_DLL) /* { */

Some other changes:

* removed the 'doc' directory as it contains the official web page of Lua