Support for IPython version 4

[rubenvereecken]

I had a lot of trouble getting this to work with my IPython. It kept spewing out deprecation errors for the used config file - the one I had to rebuild my vim against. After looking around I found out my current IPython is version 4.0, quite a surprise for myself as well. Looking here in the issues section I see version 3.0 support was added only half a year ago.

I haven't checked when 4.0 came out, but are there plans to support this? I can even jump in and help you out.

For now I'll just downgrade and see if 4.0 is somehow worth having versus worth having this plugin.

[deto]

I did a little bit of work here (see the above pull request). Simple "run this/these line(s)" works, compatibility warning messages are gone, and ":IPython" works as expected.

[rubenvereecken]

That's actually great, I'll try it out next time I need to jump into IPython. You're brave for trying your hand at this!