Split timeouts into Real-time, slow and static

[philseeley]

Currently there is one data timeout and for some data sources this is ignored as there values don't change often.

The code for not timing out is not in the Boxes, but in the Controller. It would be better for the Boxes to define how
they want the timeouts to be handled.

Therefore have timeout options per box of:

• Real-time - the default
• Infrequent - e.g. for some derived-data, like sunlight times.
• Static - e.g. for data sources like "defaults".