removed a weird characters from CMakeLists.txt, which prevents OGS_CONFIG=SP to work.
In new equation solver (OGS_CONFIG=SP), let solutions of the the deactivated domain, in which all associated entries of the matrix and vectors are zero, to zero. To do this, the zero diagonal entries of the stiffness matrix are assigned with a small number. Before the change, theses solutions just take theirs initial guess.
removed spurious piece of source code in IncorporateBoundaryConditions.