This introduces a new internally-facing view that provides information

on the updates made to existing entries on the page (along with certain

UI elements, such as the issue summary table). The client will be able

to poll for this information and dynamically update the page without a

reload.
Each update contains JSON metadata consisting of basic information on

that entry/UI element, model attributes, and view options. The update

also contains new HTML for that part of the page.
Rather than using JSON or some other standard serialization format to

represent all the resulting changes on the page, the payload instead

uses a custom format that serializes updates as:

The byte length of the JSON metadata
The JSON metadata contents
The byte length of the HTML content
The HTML content

This is more compact than using a format like JSON, as the HTML can be

represented as-is and doesn't need to be escaped when serializing. It's

faster, as the JSON can be quickly parsed and the HTML directly set in

the DOM. It's also a streamable format, allowing us down the road to

push updates directly to the page piece-by-piece.
The view allows for filtering by specific entries or entry types, and

also allows for filtering by timestamp. The entries have been extended

to support ETag generation, allowing for flexible caching of results.
An upcoming change will make use of this client-side.

Unit tests pass.
Tested the filtering options manually with a series of different

entries.
Tested the updates capabilities with the upcoming client-side change.