Support automatic refresh across browsers.

[popzip]

Scenario mentioned in #362: when using 2 different browsers, must manually refresh page to see updates.

Current architecture does not support dynamic refresh across browsers. Consideration for future - research where this is being used by customers and monitor requests for seeing this type of functionality in a MarkLogic app.

[laurelnaiad]

We have had folks asking about pushing data to the browser when it is modified by other users or external processes -- in the Samplestack context and other places (see #362 for a Samplestack case of this).

One way to do this involves having MarkLogic do an alert on the change, which would then be picked up by the middle-tier and pushed to the browser via WebSockets.

As this is an area of interest for people, we should consider this kind of enhancement for the future.