SSL and other fixes

This fixes the last security concern/other bugs that we're seeing, however it results in MathJax being disabled as that's coming over an HTTP URL so the browser rejects it. We'll need to figure out where that URL lives within IPython and pass through an "ssl: True" variable in our conf file.

They give you a recourse to download mathjax: `from IPython.external import mathjax; mathjax.install_mathjax()`

However, their downloader uses an old URL that gives a 404 now

```python
In [3]: mathjax.install_mathjax()                                                                                                                                                               
Downloading mathjax source from https://github.com/mathjax/MathJax/archive/v2.2.tar.gz                                                                                                          
---------------------------------------------------------------------------                                                                                                                     
HTTPError                                 Traceback (most recent call last)                                                                                                                     
<ipython-input-3-22246fa79997> in <module>()                                                                                                                                                    
----> 1 mathjax.install_mathjax()                                                                                                                                                               
                                                                                                                                                                                                
/usr/local/lib/python2.7/dist-packages/IPython/external/mathjax.pyc in install_mathjax(tag, dest, replace, file, extractor)                                                                     
    172         mathjax_url = "https://github.com/mathjax/MathJax/archive/%s.tar.gz" %tag                                                                                                       
    173         print("Downloading mathjax source from %s" % mathjax_url)                                                                                                                       
--> 174         response = urlopen(mathjax_url)                                                                                                                                                 
    175         file = response.fp                                                                                                                                                              
    176 

<snip>
HTTPError: HTTP Error 404: Not Found
```

Feel free to merge now, or wait until we've got that issue patched.