ENH: snappyHexMesh: add buffer layers before snapping

applications/test/syncTools/missing_cell/Allclean

applications/test/syncTools/missing_cell/Allrun

applications/test/syncTools/missing_cell/README.txt

.../test/syncTools/missing_cell/constant/transportProperties

...ications/test/syncTools/missing_cell/system/blockMeshDict

applications/test/syncTools/missing_cell/system/controlDict

...ations/test/syncTools/missing_cell/system/createPatchDict

...tions/test/syncTools/missing_cell/system/decomposeParDict

applications/test/syncTools/missing_cell/system/fvSchemes

applications/test/syncTools/missing_cell/system/fvSolution

applications/test/syncTools/missing_cell/system/topoSetDict

...ilities/mesh/generation/extrude/extrudeMesh/extrudeMesh.C

...s/utilities/mesh/generation/snappyHexMesh/snappyHexMesh.C

...tions/utilities/mesh/manipulation/subsetMesh/subsetMesh.C

.../utilities/parallelProcessing/decomposePar/decomposePar.C

...ies/parallelProcessing/decomposePar/domainDecomposition.C

...lities/parallelProcessing/reconstructPar/reconstructPar.C

...cations/utilities/surface/surfaceMeshExtract/Make/options

...utilities/surface/surfaceMeshExtract/surfaceMeshExtract.C

etc/caseDicts/annotated/extrudeMeshDict