Test which verifies the basic facilities of feComposite.

This test uses the following elements: <path>, <filter> <feImage>, <feComposite>

The test case shows six pairs of overlapping triangles depicting the six different feComposite operators. The first row shows compositing when both triangles have opacity=1. The second row shows compositing when both triangles have opacity=.5. The six columns illustrate the six types of compositing operations. The difference with filters-composite-01-f.svg is that this test does not use enable-background.