SVG 1.1 dynamic update tests

Tests dynamic updates of the 'x1' attribute of the SVGLinearGradientElement object

On success, you will see a series of "PASS" messages, followed by "TEST COMPLETE".

PASS linearGradientElement.getAttribute('x1') is "100%"
PASS linearGradientElement.getAttribute('x1') is "200%"
PASS successfullyParsed is true

TEST COMPLETE