query-handler: Truly assume oneshot queries

We pretended to earlier, but we really didn't. With this patch,
we do and the code once again matches both the code comments
and earlier commit messages.

Signed-off-by: Andreas Ericsson <ae@op5.se>
Add naemon-query.py

A shameless ripoff of the code used in Merlin, but operational
and enough to allow people to play around with the query handler
somewhat.

Signed-off-by: Andreas Ericsson <ae@op5.se>