Disable runtime statistics by default; improve usability of enabling/disabling them

Ensure that all core resources and standard subsystem resources that gather runtime statistics have statistics gathering disabled by default. The default configuration should be optimized for performance.

Ensure that the mechanism to enable/disable statistics gathering is consistent across resources (i.e. a boolean attribute with a consistent name and location in the relevant portion of the resource tree).

Implement other relevant points agreed upon in the November 2012 AS design meetings in Brno.