Added finestscheme and MaskedElements. Removedofs arg for splinefunc
Bugfix for finestscheme evaluation of trimmed element
Throw warning when triangle integration cannot be exact
Sort children
Added groups to refineddomain
Introduced TrimmedTopology
Refinement functionality
Allow for inexact integration of tetrahedrons. Throw warning!
Tensor integration
Added suppfun
Replaced "simplices" by "children" in Moisaic.pointset
Merge remote-tracking branch 'clemens/sane' into mergeclemens

Conflicts:
	nutils/element.py
	nutils/topology.py