Lua integration

I tried adding fallback Lua parsing to the master code, since I had some free time.  I've never tried to do a pull-request on github before, but I thought it might make things easier.  If you're not interested or you're already working on something feel free to ignore this.

I basically renamed the Lua parser luaparser.c and added a lua_State pointer to the tupfile struct.  I prefixed all the tests I converted to lua with lua- so stuff like t2004 exists twice in the tests directory.