tweak handling of slow/missing upstream

our fetch and render timeouts were both 20s,
causing the 'finish early' event to fire immediately before 
the upstream timeout turns it into a 400.

This moves the upstream connection timeout to 10s,
meaning unavailable servers will hit 400 instead of 'working...'.

I also removed the 'Fetched...' timing diagnostic message when the fetch fails.
minor text editing

on FAQ and error pages
don't log the URL query

it might contain credentials
Merge pull request #245 from minrk/no-log-query

don't log the URL parameters of failed requests
Updating IPython notebook text and link.
Shorted language titles to IPython/IRuby/IJulia
Fixing sympy example notebook link.
Merge pull request #238 from ellisonbg/ipython2

Updating IPython notebook text and link.
second FAQ pass

use Notebook Viewer where possible
compacting footer view #230
GitHub client shouldn't authenticate twice
Merge pull request #248 from jvns/dont-authenticate-twice

GitHub client shouldn't authenticate twice
Redirect raw.githubusercontent.com URLs as well as raw.github.com
Match 0 or 1 usercontent in RawGitHub regex
fixing up whitespace and footer tag to add a little padding at bottom of page
Merge pull request #246 from adamw523/footer

compacting footer view #230
Merge pull request #243 from minrk/slow-fetch

tweak handling of slow/missing upstream
Merge pull request #244 from minrk/copy-edit

minor text editing
more redable dates
Merge pull request #251 from Carreau/momentjs

more redable dates