IPython/Extensions/ipipe.py (xiter): Make sure that iterating...
IPython/Extensions/ipipe.py (xiter): Make sure that iterating
a string containing a single line yields the string itself as the
only item.
IPython/Extensions/ibrowse.py (ibrowse): Avoid entering an
object if it's the same as the one on the last level (This avoids
infinite recursion for one line strings).
