Minor tweaks to the query service API.
Merge branch 'rowcache'
Check dbname in rowcache invalidator.
query_rules can now filter by table names.
Improved streamlogger.

Simplified the streamlogger code.
Extended it to allow for local non-http subscribers.
Added tests.
The non-http subscription will be used for additional
monitoring and status reporting.
txlogz first cut.
Update Tools.markdown