Removed SVGElement from JSHint globals list.

This change reverts commit 91a0695717c8396fb0a48a51feaddd99dcf49b29.

The SVG interfaces were added to the browser globals collection in
JSHint 2.0.0 so defining the SVGElement as a global is no longer needed.
The grunt-contrib-jshint dependency was upgraded to version 0.5 in
commit 340e3aabb394af571ec2dee796d1ba5611ca26b1, which uses JSHint
2.0.0.