functionObjects::comfort: New functionObject to calculate fields relating to thermal comfort

Description
    Calculates the thermal comfort quantities predicted mean vote (PMV) and
    predicted percentage of dissatisfaction (PPD) based on DIN ISO EN 7730:2005.

Usage
    \table
        Property      | Description                  | Required  | Default value
        clothing      | The insulation value of the cloth | no   | 0
        metabolicRate | The metabolic rate      | no        | 0.8
        extWork       | The external work        | no        | 0
        Trad          | Radiation temperature | no | -1
        relHumidity   | Relative humidity of the air | no | 50
        pSat          | Saturation pressure of water | no | -1
        tolerance     | Residual control for the cloth temperature | no | 1e-5
        maxClothIter  | Maximum number of iterations | no       | 0
        meanVelocity  | Use a constant mean velocity in the whole domain | no |\
        false
    \endtable

    \table
        Predicted Mean Vote (PMV)   | evaluation
        + 3                         | hot
        + 2                         | warm
        + 1                         | slightly warm
        + 0                         | neutral
        - 1                         | slightly cool
        - 2                         | cool
        - 3                         | cold
    \endtable

    \verbatim
    comfortAnalysis
    {
        type            comfort;
        libs            ("libfieldFunctionObjects.so");

        executeControl  writeTime;
        writeControl    writeTime;
    }
    \endverbatim

The new tutorial case heatTransfer/buoyantSimpleFoam/comfortHotRoom is provided
to demonstrate the calculation of PMV and PPD using the comfort functionObject.

This work is based on code and case contributed by Tobias Holzmann.

Author: Henry Weller

src/functionObjects/field/Make/files

@@ -69,4 +69,6 @@ interfaceHeight/interfaceHeight.C
 
 age/age.C
 
+comfort/comfort.C
+
 LIB = $(FOAM_LIBBIN)/libfieldFunctionObjects

src/functionObjects/field/age/age.C

@@ -243,9 +243,7 @@ bool Foam::functionObjects::age::execute()
     Info<< "Min/max age:" << min(age).value()
         << ' ' << max(age).value() << endl;
 
-    store(tage);
-
-    return true;
+    return store(tage);
 }