Port of the back-end to nodejs

This ports the load/save functionality that was implemented in python in the production server to nodejs.  

With this, the devserver has 2 options for running.  It can run in "remote" mode, where /home, /load and /save urls are still proxied up to the live production server.  This is the default for the devserver.  

It can also be run in "local" mode where these urls are not proxied, but handled locally against local data.  This is how all the test cases are run.