OpenFOAM field reading: Automated the handling of <field>.orig files

Now if a <field> file does not exist first the compressed <field>.gz file is
searched for and if that also does not exist the <field>.orig file is searched
for.

This simplifies case setup and run scripts as now setField for example can read
the <field>.orig file directly and generate the <field> file from it which is
then read by the solver.  Additionally the cleanCase function used by
foamCleanCase and the Allclean scripts automatically removed <field> files if
there is a corresponding <field>.orig file.  So now there is no need for the
Allrun scripts to copy <field>.orig files into <field> or for the Allclean
scripts to explicitly remove them.

bin/tools/CleanFunctions

@@ -59,13 +59,6 @@ cleanCase()
     rm -rf jobInfo > /dev/null 2>&1
     rm -rf postProcessing > /dev/null 2>&1
     rm -rf TDAC > /dev/null 2>&1
-    rm -rf probes* > /dev/null 2>&1
-    rm -rf forces* > /dev/null 2>&1
-    rm -rf graphs* > /dev/null 2>&1
-    rm -rf sets > /dev/null 2>&1
-    rm -rf surfaceSampling > /dev/null 2>&1
-    rm -rf cuttingPlane > /dev/null 2>&1
-    rm -rf system/machines > /dev/null 2>&1
 
     if [ -d constant/polyMesh ]
     then
@@ -83,12 +76,16 @@ cleanCase()
     rm -rf constant/tetDualMesh > /dev/null 2>&1
 
     rm -rf VTK > /dev/null 2>&1
+    rm -rf sequencedVTK > /dev/null 2>&1
+
     rm -f 0/cellLevel 0/pointLevel 0/cellDist constant/cellDecomposition
 
     if [ -e system/blockMeshDict.m4 ]
     then
         rm -f system/blockMeshDict > /dev/null 2>&1
     fi
+
+    find . -name "*.orig" -type f -exec sh -c 'rm -f ${0%.*} ${0%.*}.gz' {} \;
 }
 
 removeCase()