Allow dynamic configuration of application settings

[ScottMansfield]

Netflix applications normally have a way of dynamically configuring themselves at runtime in reaction to changes in Archaius properties. There is a common library (in Java) that manages scoping these properties down to a single box running i the cloud.

Rend will not have the ability to read these fast properties, but will instead expose a common way of configuring internal properties to allow code to be dynamically configured at runtime. This could be used to, for example, disable reads from L1 at runtime to stress the L2 or do failure testing.

This will operate in conjunction with the Prana sidecar which will use the pre-existing Archaius libraries to receive property changed events and properly poke rend to update.