Support wheel package (and upload it to PyPi)

[Wheels](https://pypi.python.org/pypi/wheel) are the [new standard](http://www.python.org/dev/peps/pep-0427) of python distribution and are intended to replace eggs. Among other advantages, they offer faster installation and allow secure digital signing. 

As IPython is a pure-python [1] package compatible with Python 2 and 3,  it can be declared as a "wheel universal", in order to build a `.whl` package valid for any platform/python version. 
To build the package (It requires `setuptools > 0.8` and `wheel`. )

    $ python setup.py bdist_wheel

or (to build and upload to pypi):

    $ python setup.py bdist_wheel upload

In order to compare the results, the `.whl` is 64% lighter than the standard `tar.gz` generated through `sdist`:

	(ipython)mgaitan@traful:~/lab/ipython$ ls -hl dist/
	-rw-rw-r-- 1 mgaitan mgaitan 3,1M nov 15 18:08 ipython-2.0.0_dev-py2.py3-none-any.whl
	-rw-rw-r-- 1 mgaitan mgaitan 8,5M nov 15 17:44 ipython-2.0.0-dev.tar.gz

And it's also much faster to install

	(ipython)mgaitan@traful:~/lab/ipython$ time pip install dist/ipython-2.0.0-dev.tar.gz 
	Unpacking ./dist/ipython-2.0.0-dev.tar.gz
	  Running setup.py egg_info for package from file:///home/mgaitan/lab/ipython/dist/ipython-2.0.0-dev.tar.gz
	    [...] // clipped
	Successfully installed ipython
	Cleaning up...

	real	0m2.091s
	user	0m1.840s
	sys	0m0.396s

	(ipython)mgaitan@traful:~/lab/ipython$ time pip install dist/ipython-2.0.0_dev-py2.py3-none-any.whl 
	Unpacking ./dist/ipython-2.0.0_dev-py2.py3-none-any.whl
	Cleaning up...

	real	0m0.328s
	user	0m0.256s
	sys	0m0.068s


Moreover, `pip >= 1.4` supports wheels. (with `--use-wheel` flag). 

This will means terabytes of bandwith and energy saved :). 


[1]: although it contains data file as statics for the notebook