missing support in bzr-svn for item_keys introduced_by

[Robert Collins]

  File "/home/robertc/source/baz/bzr-test-fixes/bzrlib/repository.py",
line 1441, in item_keys_introduced_by
    file_ids = self.fileids_altered_by_revision_ids(revision_ids, inv_w)
  File "/home/robertc/source/baz/bzr-test-fixes/bzrlib/repository.py",
line 1284, in fileids_altered_by_revision_ids
    selected_keys, pb=pb),
  File
"/home/robertc/source/baz/bzr-test-fixes/bzrlib/versionedfile.py", line
856, in iter_lines_added_or_present_in_keys
    raise NotImplementedError(self.iter_lines_added_or_present_in_keys)
NotImplementedError: <bound method
FakeInventoryTexts.iter_lines_added_or_present_in_keys of
<bzrlib.plugins.svn.versionedfiles.FakeInventoryTexts object at
0x1874190>>

 affects bzr-svn
--
GPG key available at: <http://www.robertcollins.net/keys.txt>.