create animation to announce updates

[jxmot]

Use a simple, small footprint method to create some type of animation when data is updated. Each sensor should have it's own indicator.

[jxmot]

The server will inform the client in a new field within the sensor data. It will contain a value indicating any "trend" in the sensor values. Trends can be "up", "down", or "none" and the server will determine the trend and pass it along.

[jxmot]

Make client side mods first. Test with client code that determines the direction the current reading is from the last. If that works sufficiently then do not implement the server side as described above.

[jxmot]

Decided that trend detection will be client side only because it is a modification to the data display, and not data itself.

[jxmot]

The work done for this issue will be combined with issue #12

[jxmot]

First pass will produce indicators that change base on trend but are otherwise static.

[jxmot]

complete