Add diagnostics to the FEvoR slab run script.
Allow zero pressure in PISMFEvoR.
Silence a compiler warning.
Disable a kludge that adjusts SIA diffusivity near domain boundaries.

I think this is what breaks our "slab on a slope" setup.
No need for temp. storage in IceModel::putTempAtDepth() (port to dev).
Move PS_EISMINTII from stc/eismint to src/coupler. Port to dev.

This makes it easier to re-use some code.
Add "-surface fevor" (built on top of PS_EISMINTII).
Do *not* keep surface slope constant.

Now we keep the *bed* slope constant and use the Mahaffy scheme to
approximate the thickness gradient. (In the slab on a slope setup
thickness *is* periodic.)
Minor: re-use a variable.
Rename an option: we're prescribing bed slope, not surface slope.
Change initial ice thickness to avoid aligning ice thickness with the
vertical grid.

(If we have a grid level right at ice thickness we become sensitive to
rounding errors during initialization.)
Update run script.

- More diagnostics
- Turn off enthalpy evolution (for now)
- Save in z,y,x order