Push some of Series.ix into Series.__getitem__/__setitem__

[wesm]

Should be able to do stuff like:

ts[date1:date2]

to mirror ts.ix[date1:date2]. Should respect integer labels while Series.ix will not

[changhiskhan]

Why not push all of it into getitem/setitem?

def getitem(self, key):
self.ix[key]

def setitem(self, key, value):
self.ix[key] = value

[wesm]

Oof. Please steer clear of this issue, it's full of performance landmines. I need to set up some benchmarks so I can evaluate all of the use cases

[wesm]

In principle having all of it in getitem/setitem would be nice. but the use cases are complex

[changhiskhan]

sounds like a reasonable approach. i'll let you take this one then :)

[wesm]

Alright, this is done. Need to document the related API changes and add lots of WARNING, WARNING