Make some private process* methods in AbstractHtmlDataTable protected

We are extending the datatable component and for that have to manually change some method signatures from private to protected. If there is no special reason why they should be private, make them generally protected would be nice.

org.apache.myfaces.component.html.ext.AbstractHtmlDataTable:

• protected void processFacets(FacesContext context, int processAction)
• protected void processColumnFacets(FacesContext context, int processAction)
• protected void processColumnChildren(FacesContext context, int processAction)
• protected void process(FacesContext context, UIComponent component, int processAction)