Added support for nozzle offsets in G10 command
Disable heater timeout if the time limit is set to zero or negative
Don't send non-error responses to the web interface unless the
corresponding command also came from the web interface
Added support for aux input from serial. Need to finish this by making
serial transmission interrupt-driven.
Incoming network requests can now span multiple TCP messages. Max upload
buffer increased to 2048. Also return layerHeight and generatedBy values
when asking for fileinfo on a gcode file. This is an interim commit that
needs cleaning up before release.