Limit for queries shouldn't be set by the user

[echox]

During paging content the user can define the limit for the SQL-Query. This is a possible DoS-Vector since a very small request can produce queries with really large results on the server, for example dump the whole database (updates?offset=25&limit=99999).
The maximum limit should be configurable and use a sane default.

[mvitz]

Can you check #185 and merge it if this fix is acceptable for you? ;-)