Add a custom fontconfig setup and ship Cantarell as part of it.
This should hopefully make it so that the tests always see the
same default font, as long as you have FONTCONFIG_FILE set up
correctly.
Update all affected tests.
Arrange things so that non-child parameters
are always printed before the children. This
greatly helps with readability, which really
suffers when there's hundreds of lines of indented
children between the node start and its parameters.
Update all affected tests.
