Sage crashes if run with a new version of IPython

[Marc Culler]

The problem is that sage/repl/display/formatter.py uses the function:    IPython.utils.py3compat.unicode_to_str

which does not exist in the current IPython.

That function is a no-op in Python3.  (In Python2 it converts a unicode byte sequence to a python string.)  So it could be removed from formatter.py without causing any problems.

- Marc

[Dima Pasechnik]

It's already fixed, just not merged yet.