Issue #71: G17, G18, G145: check font size and weight to determine level
background image testing added
Added test for linear gradients
Add support for all gradient types and multiple color stops
better testing for gradients using helper lib
added a radial gradient
labels fixed, test-7c should is readable on screen, not according to the tests
test renumbered, getGradient checks for background color
function comments added
cleanup
cleanup
duplicate line
support added to detect non-parent elements behind current element
added traverseVisualTree helper, added test for background color, image and gradient
if simplified
Merge branch '71-test-for-wcag-technique-g145-g18-and-g17-ensuring-that-a-contrast-ratio-exists-between-text-and-images-of-text-and-background-behind-the-text' of https://github.com/attiks/quail into attiks-71-test-for-wcag-technique-g145-g18-and-g17-ensuring-that-a-contrast-ratio-exists-between-text-and-images-of-text-and-background-behind-the-text