rhoSimpleFoam: Added "consistent" option to replace rhoSimplecFoam

See tutorials/compressible/rhoSimpleFoam/squareBend

SIMPLE
{
    nNonOrthogonalCorrectors 0;
    rhoMin          0.1;
    rhoMax          1.0;
    transonic       yes;
    consistent      yes;

    residualControl
    {
        p               1e-3;
        U               1e-4;
        e               1e-3;

        // possibly check turbulence fields
        "(k|epsilon|omega)" 1e-3;
    }
}

relaxationFactors
{
    fields
    {
        p               1;
        rho             1;
    }
    equations
    {
        p               1;
        U               0.9;
        e               0.9;
        k               0.9;
        epsilon         0.9;
    }
}