Increased timeout.

Gunicorn ought to kill itself after 30 seconds, so doing it ourselves at 28
secs is close to the margin, but taking the extra 3 seconds (compared to the
old 25 and even older 20 secs) seems to me to be the right choice.
Showing nicer error message and reloading graphs automatically.
Merge pull request #50 from lizardsystem/reinout-reload-faulty-graphs-automatically

Reload faulty graphs automatically