reflect.DeepEqual() empirically uses shallow equality for map keys but deep equality for
map values.  (http://play.golang.org/p/4zQk_WLqlg)  Although the behavior is reasonable,
a casual reader might be surprised by it.

The documentation for DeepEqual says that it "will scan members of arrays, slices,
maps, and fields of structs", but the language spec does not use the word
"members".  It would be clearer to use the (defined) term "elements"
instead so that the reader doesn't have to guess whether "members" is meant to
include "keys".