BUG: Several tutorial failures after commit 2d036ca00

With the change in behaviour of the inverseDistanceDiffusivity (commit 2d036ca00) to use a run-time selectable wall distance, users are now required to add wall dist construction info into the fvSchemes dictionary. Also, the computed diffusivity has dimensions of 1/m as opposed to dimensionless.

Tutorials:

heatTransfer/buoyantBoussinesqSimpleFoam/iglooWithFridges:
    log.snappyHexMesh: keyword patchDist is undefined in dictionary "system/fvSchemes": fvSchemes

mesh/moveDynamicMesh/SnakeRiverCanyon:
    log.moveDynamicMesh: keyword patchDist is undefined in dictionary "system/fvSchemes": fvSchemes

mesh/moveDynamicMesh/relativeMotion/box2D_moveDynamicMesh:
    log.moveDynamicMesh: keyword patchDist is undefined in dictionary "system/fvSchemes": fvSchemes

multiphase/potentialFreeSurfaceDyMFoam/oscillatingBox:
    log.potentialFreeSurfaceDyMFoam: keyword patchDist is undefined in dictionary "system/fvSchemes": fvSchemes