Upper Limit for projectdoc Queries

To be DC compliant the projectdoc Toolbox needs to put an upper limit to the result set. This is to be a configuration option in the administration screen and defaults to a value of 100.

In case the result set is actually larger than 100 hits, the macros need to render a box with a warn message. Users should then put additional constraints on their queries.

It may make sense to provide paging in a future version of the projectdoc Toolbox. Since the design goal is to be printable, the paging would only be an alternative representation of the warning box. There will be no alternative view for PDF export where the query renders more than the specified maximum of hits, since this would violate the DC requirements.