code: function(oInstance) {
  
  			// ensure that the instance count is never negative
  			var iInstanceCount = Math.max(this._iInstanceCount - 1, 0);
  
  			// deactivate the instance customizing
  			if (oInstance) {
  				this.deactivateCustomizing(oInstance);
  			}
  
  			if (iInstanceCount === 0) {
  
  				// deactivcate the customizing
  				this.deactivateCustomizing();
  
  				// remove the custom scripts and CSS files
  				this.removeIncludes();
  
  			}
  
  			this._iInstanceCount = iInstanceCount;
  
  		}
docs: Terminates the manifest and does some final clean-up.
  @private