Optimized PetscSparseMtrx::buildInternalStructure. It is now faster and uses a less memory. Also, -mat_type sbaij should now work in parallel.
Added "-ksp_type cg" to parallel tests. This gives a huge performance increase (compared to dead slow).
Reworked logic in dofmanager to allow for stokes problems without having to specify dofidmask in every node.