Allow support for absolute url clip-path.

[aaronmallen]

When disabling the # url convention in an angular app with:

$locationProvider.html5Mode({enabled: true, requireBase: false})

the clipEdge property was not working in my environment. Essentially by adding the full url before the anchor tag on the g element calling clip path, I was able to successfully clip the bars area.

<!-- given the url http://localhost:9000/demo -->

<!-- this is what is provided by the directive, which does not work. -->
<g clip-path="url(#nv-chart-clip-path-6907)">...</g>

<!-- providing absolute url works -->
<g clip-path="url(http://localhost:9000/demo#nv-chart-clip-path-6907)">...</g>

[aaronmallen]

angular/angular.js#8934