[docs] -b option undocumented (issue 11681)

[ncoghlan at gmail.com]

http://bugs.python.org/review/11681/diff/19720/Doc/using/cmdline.rst
File Doc/using/cmdline.rst (right):

http://bugs.python.org/review/11681/diff/19720/Doc/using/cmdline.rst#newcode196
Doc/using/cmdline.rst:196: Issue a warning when comparing :class:`bytes`
with :class:`bytearray`.
For 2.x, :class:`unicode` is the relevant cross-reference here.

It may also be worth adding a second paragraph explicitly mentioning the
difference from the Python 3 flag:

====
Note that, unlike the corresponding Python 3.x flag, this will NOT emit
warnings for comparisons between :class:`str` and :class:`unicode`.
Instead, the ``str`` instance will be implicitly decoded to ``unicode``
and Unicode comparison used.
====

http://bugs.python.org/review/11681/diff/19720/Doc/using/cmdline.rst#newcode199
Doc/using/cmdline.rst:199: .. versionchanged:: 3.5
3.x versionchanged notes are left out of the 2.x docs

However, this should have a "versionadded" note for 2.6 (since it was
added as part of a merge back from the Py3k branch).

http://bugs.python.org/review/11681/