Scalability and StringListCodec

Now that I'm worrying about Large Scale Hackystat applications, I've run across a scalability issue in StringListCodec. It currently hardwires the maximum string size as 99,999 and the maximum number of strings as 9,999.

These translate to constraints on (a) the size of a sensor data instance and (b) the number of sensor data instances that can be sent in any individual Hackystat SOAP transmission.

Fortunately, this is easy to fix: these are constants that could potentially be overridden, for example, by a property value. The cost of increasing them is an increase in the "fixed cost" of a sensor data transmission, due to the way StringListCodec works.