FATAL ERROR When running in demo mode

[garrettpatterson]

Running the server crashes with "FATAL ERROR: CALL_AND_RETRY_2 Allocation failed - process out of memory" after about 8 hours left on in the DEV/DEMO mode. This may not occur when running connected to the Keg.

[dcarney]

I've added a new function to the keg.io class that prints the current memory usage for the process once per minute when running in DEVMODE. To see the output, set the logging level in conf/log4js.json to TRACE and check the resulting TRACE events.

To get a long-running history of the mem usage, it might be easiest to configure log4js to send these trace events to a seperate file. See the appenders in conf/log4js.json for examples.