IPython 3.0 Support

Maybe, just maybe ein now works under both IPython 2.x and IPython 3.0
(or what is the development version as of this commit). And by works I
mean open, closing, saving notebooks and communicating with the IPython
kernel. It is good.

Also fixed a bug in kernelinfo - os.uname is not implemented in Windows
(or mac, probably), but I think socket.gethostname() is available on all
three platforms.