Clipping to an empty path must prevent all drawing.

Spotted by LayoutTests/canvas/philip/tests/2d.path.clip.empty.html.
DumpRenderTree: fix off-by-one error

The last column and line of pixel tests were not imported in the tested bitmap.
There could be garbage there, resulting in false negatives in the
testsuite.
Cookie Jar: fix handling of httpOnly cookies.

They are hidden from the DOM (so JS can't get to them), but not from the
HTTP headers.
Disable texture mapper again.

It turns out this is not really what we want. Instead, provide an Haiku
specific GraphicsLayer implementation. We should probably make it do
something.