tutorials: Consistency of All* scripts

Various minor changes to tutorial scripts. In particular, ensuring that
they all change to the containing directory so that batches of tutorials
can be run easily from the root of the installation.

tutorials/multiRegion/CHT/shellAndTubeHeatExchanger/Allmesh.layers

@@ -1,7 +1,7 @@
 #!/bin/sh
+cd ${0%/*} || exit 1    # Run from this directory
 
-cd ${0%/*} || exit 1
-
+# Source tutorial run functions
 . $WM_PROJECT_DIR/bin/tools/RunFunctions
 
 # Create the initial block mesh and decompose
@@ -27,3 +27,5 @@ runParallel -a snappyHexMesh -overwrite
 
 # Split the mesh into regions
 runParallel splitMeshRegions -cellZones -defaultRegionName solid -overwrite
+
+#------------------------------------------------------------------------------