Enable Series objects to optionally have a name associated with them

[wesm]

This would be easy to do / unobtrusive:

>>> s = Series(values, index, name='foo')
>>> s.name

[wesm]

According to @jseabold "Two somewhat related observations. Unless I missed it, it might be
nice if Index had a names attribute like MultiIndex. The same for
Series, maybe called columns like DataFrame. I was needing one when
trying to allow joining a Series to a DataFrame until I found insert,
though insert doesn't allow you to append. Of course, I could just do
df['new_col'] = some_series, but I like the alignment index checking
in join and friends.
"

[wesm]

This was done in 0.4.3