Add fields into RC for Vizier ML experiments.

Add fields into RC for Vizier ML experiments.

This patch adds fields into the RC data structure for the Vizier.

The added fields allow control of some extra rate control parameters
and rate distortion.

This patch also adds functions to initialize the various parameters
though many are not yet used / wired in and for now all are set to
default values. Ultimately many will be set through new command
line options.

Change-Id: I41591bb627d3837d2104fb363845adedbddf2e02