setup.py: Mention Jinja and CherryPy as requirements

setup.py: Mention Jinja and CherryPy as requirements

Unfortunately, none of the current Python installation tools
(easy_install, pip, others?) actaully use the `Requires` field that
this populates [1,2], and it's gone since PEP 345, replaced by
`Requires-Dist` [2,3,4].  Eventually a new packaging library
(distutils2, packaging, distlib, ...) will land in the Python standard
library and we can use whatever interface it provides for specifying
dependencies [5].

[1]: http://blog.doughellmann.com/2007/11/requiring-packages-with-distutils.html
[2]: http://ziade.org/2010/02/10/pep-345-and-386-accepted-summary-of-changes/
[3]: http://www.python.org/dev/peps/pep-0345/#requires-dist-multiple-use
[4]: http://www.python.org/dev/peps/pep-0426/#requires-dist-multiple-use
[5]: http://ncoghlan_devs-python-notes.readthedocs.org/en/latest/pep_ideas/core_packaging_api.html