Inconsistent Series subsetting behaviour
Series in 0.7 RC1 have some weird behaviour when selecting by index.

> > > y
> > > a    0
> > > 0    1
> > > 1    2
> > > Name: a
> > > y[0]
> > > 1                                               # expected
> > > y[[0,1]]
> > > a    0                                         # wrong?
> > > 0    1
> > > Name: a
> > > y[[1,2]]
> > > 0    1
> > > 1    2
> > > Name: a
> > > y.ix[[0,1]]                            # this also doesnt work
> > > a    0
> > > 0    1
> > > Name: a
