CC fixes & PearlConfigChangedNotification.

[ADDED]     Make a PearlCCMenuItemBlock that does nothing.
[UPDATED]   Expose -doLoad of PearlCCMenuLayer so it can be overridden.
[FIXED]     Avoid infinite loop when changing something in PearlCCMenuLayer that causes a reset.
[FIXED]     Bad positioning of PearlCCShadeLayer's background if it's set just after the animation.
[ADDED]     PearlConfig now posts a PearlConfigChangedNotification when one of its setters fires.