Add two taps modification procedures to the sys schema via the
StatisticsService.
Remove unused constants.
Remove the JMX bean access to the Taps.
merge tjoneslo: Add two taps modification procedures to the sys schema

Merge pull request #1221 from tjoneslo/sql-layer/create_taps_procedures
https://github.com/FoundationDB/sql-layer/pull/1221