ENH: added clean up function remove0DirFields (RunFunctions)

- less typing than before and avoids relying on bash-specific behaviour
  (fixes #3448)

ENH: add -region support for cleanFaMesh and cleanPolyMesh

CONFIG: add bash completion help for -area-region

ENH: general improvements for regionProperties

- robustness and failsafe for foamListRegions, regionProperties
- additional global model switches for regionModels

tutorials/basic/chtMultiRegionFoam/2DImplicitCyclic/Allmesh

@@ -13,10 +13,11 @@ restore0Dir
 runApplication splitMeshRegions -cellZones -overwrite
 
 # Remove fluid fields from solid regions (important for post-processing)
+fields="nut alphat epsilon k U p_rgh"
+
 for region in $(foamListRegions solid)
 do
-    rm -f 0/$region/{nut,alphat,epsilon,k,U,p_rgh}
-    rm -f processor*/0/$region/{nut,alphat,epsilon,k,U,p_rgh}
+    remove0DirFields -region "$region" -- $fields
 done
 
 for region in $(foamListRegions)