cleanup wmake scripts

- match comments to names of scripts
  - remove comments about using C-shell (not true anymore)
  - use 'assert' style syntax in places instead of if/then/fi
  - wcleanMachine supports multiple arguments

wmake/wmakeDerivedFiles

@@ -32,14 +32,17 @@
 #
 #------------------------------------------------------------------------------
 
-if [ ! -d $WM_OPTIONS ]
+if [ ! -d "$WM_OPTIONS" ]
 then
-    echo The $WM_OPTIONS directory does not exist, exiting \!
+    echo "The $WM_OPTIONS directory does not exist, exiting"
     exit 1
 fi
 
 # change to the $WM_OPTIONS directory
-cd $WM_OPTIONS
+cd $WM_OPTIONS 2>/dev/null || {
+   echo "Could not change to directory '$WM_OPTIONS'"
+   exit 1
+}
 
 # Find and keep macro definitions in files list
 grep "=" files > filesMacros
@@ -141,5 +144,4 @@ rm files.$$
 
 cd ..
 
-
 #------------------------------------------------------------------------------