A bit of cleanup in CBS. Mainly using MomentumBalance instead of AuxMomentumBalance whenever possible (since they have the same numbering) which simplifies code a bit.
Cleanup in SUPG, local scopes for variables and removed unnecessary reimplementations of some functions from EngngModel.
Introduced Velocity and Pressure UnknownNumberingScheme's for CBS algorithm (currently, they make no pratical difference but could make EID redundant)
Extending tr1_2d_cbs to work with EID_MomentumBalance_ConservationEquation, letting the numbering scheme split into velocity and pressures.
Removing need for AuxMomentumBalance by simply storing the temporary uncorrected velocity in the velocityfield.
Made UnknownNumberingScheme keep track of number of equations for CBS algorithm.
Hopefully fixing OOFEG build errors in new XFEM code.