Add dependencies and finish the py-tornado package.

This adds the following packages:

 py-backports-shutil-get-terminal-size  py-nbformat
 py-backports-ssl-match-hostname        py-pathlib2
 py-entrypoints                         py-pickleshare
 py-futures                             py-pip
 py-ipykernel                           py-prompt-toolkit
 py-ipython-genutils                    py-ptyprocess
 py-ipywidgets                          py-simplegeneric
 py-jupyter-client                      py-singledispatch
 py-jupyter-console                     py-terminado
 py-jupyter-core                        py-traitlets
 py-jupyter-notebook                    py-wcwidth
 py-monotonic                           py-widgetsnbextension
 py-nbconvert

var/spack/repos/builtin/packages/py-pycurl/package.py

@@ -35,8 +35,9 @@ class PyPycurl(Package):
     version('7.43.0', 'c94bdba01da6004fa38325e9bd6b9760')
 
     extends('python')
+    depends_on('python@2.6:')
     depends_on('py-setuptools', type='build')
-    depends_on('curl')
+    depends_on('curl@7.19.0:')
 
     def install(self, spec, prefix):
         setup_py('install', '--prefix={0}'.format(prefix))