ENH: suppress Info output for some cases (issue #722, #893)

- add additional control via a Foam::infoDetailLevel flag, which is
  supported by a 'DetailLevel' macro.  Eg,

      DetailLevel << "some information" << nl

- When infoDetailLevel is zero, the stdout for all Foam::system() calls
  are also redirected to stderr to prevent child output from
  appearing on the parent.

- close stdin before exec in system call.

bin/tools/RunFunctions

@@ -56,9 +56,6 @@ notTest()
 # Extract 'numberOfSubdomains' from system/decomposeParDict
 # (or alternative location).
 #
-# Note that '#include' and other directives are disabled - only entries that
-# are in the dictionary are considered.
-#
 # On failure:
 #    return '1'
 #    exit status 1
@@ -68,14 +65,14 @@ getNumberOfProcessors()
     local dict="${1:-system/decomposeParDict}"
 
     # Re-use positional parameters for automatic whitespace elimination
-    set -- $(foamDictionary -disableFunctionEntries -entry numberOfSubdomains -value "$dict" 2>/dev/null)
+    set -- $(foamDictionary -entry numberOfSubdomains -value "$dict" 2>/dev/null)
 
     if [ "$#" -eq 1 ]
     then
         echo "$1"
     else
         echo "Error getting 'numberOfSubdomains' from '$dict'" 1>&2
-        echo 1 # serial as fallback
+        echo 1      # Fallback is 1 proc (serial)
         return 1
     fi
 }
@@ -84,9 +81,6 @@ getNumberOfProcessors()
 #
 # Extract 'application' from system/controlDict
 #
-# Note that '#include' and other directives are disabled - only entries that
-# are in the dictionary are considered.
-#
 # On failure:
 #    return 'false' which is also a command (ie, shell builtin or /bin/false)
 #    exit status 1
@@ -94,14 +88,14 @@ getNumberOfProcessors()
 getApplication()
 {
     # Re-use positional parameters for automatic whitespace elimination
-    set -- $(foamDictionary -disableFunctionEntries -entry application -value system/controlDict 2>/dev/null)
+    set -- $(foamDictionary -entry application -value system/controlDict 2>/dev/null)
 
     if [ "$#" -eq 1 ]
     then
         echo "$1"
     else
         echo "Error getting 'application' from system/controlDict" 1>&2
-        echo false
+        echo false  # Fallback
         return 1
     fi
 }