ENH: Added new propellerInfo function object

Calculates propeller performance and wake field properties.

Controlled by executeControl:
- Propeller performance
  - Thrust coefficient, Kt
  - Torque coefficient, 10*Kq
  - Advance coefficient, J
  - Open water efficiency, etaO
  - Written to postProcessing/<name>/<time>/propellerPerformance.dat

Controlled by writeControl:
- Wake field text file
  - Wake: 1 - UzMean/URef
  - Velocity in cylindrical coordinates at xyz locations
  - Written to postProcessing/<name>/<time>/wake.dat
- Axial wake field text file
  - 1 - Uz/URef at r/R and angle
  - Written to postProcessing/<name>/<time>/axialWake.dat
- Velocity surface
  - Written to postProcessing/<name>/surfaces/time>/disk.<fileType>

Usage

    Example of function object specification:
    \verbatim
    propellerInfo1
    {
        type            propellerInfo;
        libs            (forces);
        writeControl    writeTime;

        patches         ("propeller.*");

        URef            5; // Function1 type; 'constant' form shown here
        rho             rhoInf; // incompressible
        rhoInf          1.2;

        // Optionally write propeller performance data
        writePropellerPerformance yes;

        // Propeller data:

        // Radius
        radius          0.1;

        rotationMode    specified; // specified | MRF

        // rotationMode = specified:
        origin          (0 -0.1 0);
        n               25.15;
        axis            (0 1 0);

        // Optional reference direction for angle (alpha) = 0
        alphaAxis       (1 0 0);

        //// rotationMode = mrf
        //// MRF             MRFZoneName;
        //// (origin, n and axis retrieved from MRF model)

        // Optionally write wake text files
        // Note: controlled by writeControl
        writeWakeFields yes;

        // Sample plane (disk) properties
        // Note: controlled by writeControl
        sampleDisk
        {
            surfaceWriter   vtk;
            r1              0.05;
            r2              0.2;
            nTheta          36;
            nRadial         10;
            interpolationScheme cellPoint;
            errorOnPointNotFound false;
        }
    }
    \endverbatim

    Where the entries comprise:
    \table
        Property        | Description                   | Required | Deflt value
        type            | Type name: propellerInfo      | yes      |
        log             | Write to standard output      | no       | no
        patches         | Patches included in the forces calculation | yes |
        p               | Pressure field name           | no       | p
        U               | Velocity field name           | no       | U
        rho             | Density field name            | no       | rho
        URef            | Reference velocity            | yes      |
        rotationMode    | Rotation mode (see below)     | yes      |
        origin          | Sample disk centre            | no*      |
        n               | Revolutions per second        | no*      |
        axis            | Propeller axis                | no*      |
        alphaAxis       | Axis that defines alpha=0 dir | no       |
        MRF             | Name of MRF zone              | no*      |
        originOffset    | Origin offset for MRF mode    | no       | (0 0 0)
        writePropellerPerformance| Write propeller performance text file | yes |
        writeWakeFields | Write wake field text files   | yes      |
        surfaceWriter   | Sample disk surface writer    | no*      |
        r1              | Sample disk inner radius      | no       | 0
        r2              | Sample disk outer radius      | no*      |
        nTheta          | Divisions in theta direction  | no*      |
        nRadial         | Divisions in radial direction | no*      |
        interpolationScheme | Sampling interpolation scheme | no* | cell
    \endtable

Note
- URef is a scalar Function1 type, i.e. supports constant, table, lookup values
- rotationMode is used to set the origin, axis and revolutions per second
  - if set to 'specified' all 3 entries are required
    - note: origin is the sample disk origin
  - if set to 'MRF' only the MRF entry is required
    - to move the sample disk away from the MRF origin, use the originOffset
- if writePropellerPerformance is set to on|true:
  - propellerPerformance text file will be written
- if writeWakeFields is set to on|true:
  - wake and axialWake text files will be written
- if the surfaceWriter entry is set, the sample disk surface will be written
  - extents set according to the r1 and r2 entries
  - discretised according to the nTheta and nRadial entries