Installation should not require Cython

pysam already follows the recommendation by Cython developers not to
require Cython to be installed and to instead distribute the compiled C
files, as recommended here:
http://docs.cython.org/src/reference/compilation.html#distributing-cython-modules

Currently, since an install_requires directive containing Cython is passed
to setup(), Cython will always be installed when running 'python setup.py
install' or 'pip install pysam'. This commit removes 'install_requires'.
Merge pull request #47 from marcelm/master

Installation should not require Cython
Do not attempt to import ez_setup since it does not exist.

Alternatively, ez_setup.py could be added to the distribution, but it appears
no one has ever complained about it not being there. Probably most people
have setuptools installed already, so just rely on that.
Merge pull request #52 from marcelm/master

Do not attempt to import ez_setup since it does not exist.
Thanks
Merge branch 'master' into pysam-0.8.1