[META] Indexing and agent management UI

[msm-cert]

This is a very ambitious project, that is planned as a main feature of v1.5 release (and the last mquery feature).

The idea is to make it possible to configure and manage every (well, almost every) aspect of mquery from the web UI. Especially indexing, which was the most repeatedly asked feature request since mquery was created.

To do this we'll have to heavily redesign... a lot of things in the UI. In return we'll get a more user-friendly interface overall, I hope.

Another thing we have to do is to add a mquery "manager" agent to ursadb. This is unfortunately not avoidable, for reasons described below. This comment is a meta-comment for tracking the index management UI. I'll add more detailed tasks later.