Start with faceted browse on all documents if query string is empty

[mlt]

I don't know if this is intentional, but it might be nice to start with showing available facets right away, i.e. set theQuery to new MatchAllDocsQuery when query is empty.

[mirkosertic]

There is no paging implemented currently. Without effective paging, this would fillupp app application memory and terminate the JVM. So before this can be implemented, paging must be implemented,