Make form.coefficients() include coordinates from integration domains.
Include integration domain coordinates in integral_data coefficients (cascades to reduced_coefficients, enabled_coefficients, element lists etc).
Work on getting highorder up and running. A bit nasty this renumbering business at the moment but it works.
Rework signature computation a bit (again). Should be correct now when
a Domain references a Coefficient which also must be renumbered.
Bugfix in signature computation.
Bugfix in facet normal for manifold surface. Also loosen checks on domain compatibility a bit.