Reverse the output from _follow_also

Reverse the output from _follow_also

Turns out when we follow the export tree we return the list in the order we
discovered, which is the inverse of the order we want. This wasn't ever a
problem before because nobody has tried exporting more than one level off of
Moose. Someone has now, so we need to reverse the entire list.

Also we have added tests for second-order exports (exporting overridden
exports)