Remove luaL_reg macro definition no longer needed

and simplify lua_load compatibility macro.

Note that in order to successfully compile with
Lua 5.2.0 we still need to add LUA_COMPAT_ALL
to CPPFLAGS. Detection in config.m4 is still
missing.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1239030 13f79535-47bb-0310-9956-ffa450edef68