ENH: Function objects - updated logic to determine whether or not to instantiate a time-based function object.  Fixes #439

ENH: Feature noise additions

See merge request !98

Both point- and surfaceNoise utilities can operate on multiple input
files.  However, if the files had the same name, the output would be
overwritten.  To avoid this, the output files are now written to a
sub-directory including the path '/input<input-file-index>/', e.g.

  postProcessing/noise/surfaceNoise/input0/nearWall/[fft|oneThirdOctave]

An optional 'outputPrefix' can be included (defaults to empty), e.g.
when set to 'test1':

  postProcessing/noise/test1/surfaceNoise/input0/nearWall/[fft|oneThirdOctave]

- easier to test or use different versions

- change WM_CXXFLAGS to -std=c++11 instead of -std=c++0x

- adjust so that the final -option is taken. This is consistent with
  other Unix tools.

ENH: short-circuit to avoid directory check on non-master node

Merge branch 'feature-noise-additions' of develop.openfoam.com:Development/OpenFOAM-plus into feature-noise-additions

- the regex was not being unset on assignment.
- drop unused recompile() method as being dubious

- tends to obscure what is going on and isn't needed either.

STYLE: adjust documentation. Accept std::string as parameter in more places.

- the purpose is more explicit, without needing to check documentation
  about what the bool parameter means.

STYLE: improve formatting of fileName documentation

Fixes #416

Closes #416

See merge request !96

- Limit output to frequency range given by fLower and fUpper (if supplied)
- Enable noise models to be run outside of $FOAM_CASE directory
  - if relative paths are used, $FOAM_CASE is prepended to the noise
    dict and input file names
- Enable output to be customised, e.g.

    // Optional write options dictionary (all default to 'yes')
    writeOptions
    {
        writePrmsf  no;
        writeSPL    yes;
        writePSD    yes;
        writePSDf   no;
        writeOctaves yes;
    }