Merge branch 'feature/cache'
Adding retrospective predictor. When viewing historical data, time and sg become stale via a strikethrough. Focus now line is fixed at 30 minutes less of the extent and if sg if not within a tolerance of time, sg is displayed as "---".
Update client.js
Merge pull request #18 from nightscout/retrospective-prediction

Adding retrospective predictor. When viewing historical data, time and s...
Merge pull request #2 from nightscout/master

Merge retrospective-prediction
Improved caching headers:

Thanks to advice by Adrien de Croy I added/updated the following sample
headers.

cache-control: public, max-age=2592000
expires: Thu Jul 24 2014 17:16:14 GMT-0700 (PDT)
Arr-Disable-Session-Affinity: True
Updated README instructions
Updated nightscout.appcache
Small rework of the static server
Reworked to support Express.

Upgraded from node-static to Express, and now the site caches like a
champ!
Full Caching with Express,

Upgraded from node-static to express.
Upgraded from node-static to Express,

and now the site caches like a
champ!
put everything in a static directory

Tested by deleting everything, running npm install from scratch.
This helps ensure that only the files in the static subdirectory can be served.
Should eliminate serving config files via http.
Merge pull request #3 from nightscout/express-cache

move static files into /static
Disable caching for /pebble

and other dynamic elements.
Pebble class experiment.

This isn’t used at the current time.
Fixed "expires:" header format error.

Added “dateformat” package. Plus some code reorganization.
Fixed "expires:" header format error.

Added “dateformat” package. Plus some code reorganization.
Fixed "expires:" header format error.

Added “dateformat” package. Plus some code reorganization.
Fixed "expires:" header format error.

Added “dateformat” package. Plus some code reorganization.