improvements to ScalarEq, EulerEq, SRHD
Accumulated various changes
- draft for 2d SRHD evolution
- rework ScalarEq 1d to use new broadcast routines
- use
force=true
on callbacks before evolution to make sure initial data is outputted - updated ref tests because of previous point
- rework
EulerEq
and fix bdry conditions to be able to evolve sod shock tube test with entropy viscosity