New application for testing contact constraints and split preconditioners.
Tests of (new) GluedContactConstraint and MechanicalContactConstraint (glued model) with and without Splits in 3D.
The new implementation of GluedContactConstraint seems to have experienced a regression.
MechanicalContactConstraint seems to have a substantially incorrect Jacobian.
For details see the report in tests/split_constraint_contact/3D/glued subdirectory.