(PDB-660) Throw deprecation warning for 'event-query-limit' and fix a docstring

Signed-off-by: Ken Barber <ken@bob.sh>
Merge pull request #975 from kbarber/ticket/master/pdb-660-events-streaming

(PDB-660) Enable event streaming and provide other streaming cleanups
(PDB-658) Move reports endpoint over to the new query engine

All existing reports functionality works with the new query engine. In
addition to what was previously supported, the following new features
were added once it was moved over:

Allows querying on the following new fields:

puppet_version
report_format
configuration_version
start_time
end_time
receive_time (though not really useful without >, <, <=, >= which has not been done yet)
transaction_uuid

Reports also now supports more of the "standard" query operators such as:

or
~ (regex)
in
not
Merge pull request #977 from senior/ticket/master/pdb-658-moving-reports-to-qe

(PDB-658) Move reports endpoint over to the new query engine
(PDB-660) Turn on streaming for nodes end-point

This turns on streaming for the nodes end-point.

Signed-off-by: Ken Barber <ken@bob.sh>