Fix errors 'undefined is not a function', 'controlType.inheritsFrom is not a function', and others, which appear to occur primarily in older versions of some browsers (Chrome, Firefox), as well as Safari (probably due to it's long release cycle). The _linkAttributes method gets the associated control for an element being linked via its 'control' property (added by MsAjax during template rendering and linking). It then checks to see if the 'control' is a component by calling the 'inheritsFrom' method of the control's constructor function. In recent years, some browsers have implemented part of the HTML spec that calls for a 'control' property which returns the 'labelled control', which would be a DOM element. In some of these browsers' early implementations the constructor of the labelled control (if one existed) would be a DOM element constructor, which was not a true function. This would cause the inheritsFrom check to throw an error, since inheritsFrom is a function that is added by MsAjax to the Function prototype. To get around this error, check for the existence of the 'inheritsFrom' method before calling it. This does not address the question of resolving conflict between the DOM property and the property that is added by MsAjax, but does get us around unnecessary errors when the element being linked (a label) has already detected a labelled control at the start of linking, because the control is contained within the label.