version 3.4.3
   * raise an error if lane generator libs specification contains a lib more than once
   * bit32 is a valid lib name in the libs specification (silently ignored by the Lua 5.1 build)
   * improved lanes.nameof to search inside table- and userdata- metatables for an object's name
   * fixed an unwarranted error when trying to discover a function name upon a failed transfer
   * contents of package.[path,cpath,preload,loaders|searchers] are pulled *only once* inside keeper states at initialisation
   * Lua function upvalues equal to the global environment aren't copied by value, but bound to the destination's global environment
     especially useful for Lua 5.2 _ENV
   * fixed loading of base libraries that didn't create the global tables when built for Lua 5.2