SpalartAllmarasDES now derived from DESModel class

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1918
Patch provided by Richard Jones

maxIters could be made an option input if 20 is not sufficient for
difficult cases.

The resetAMI in the cyclicAMI would go up to cyclicACMI and do the
initPatchFaceAreas again - but with already masked areas

The old version of regionSplit would hand out regions one by one. This
is a big problem when there are lots of regions - the extreme being
in the decompositionMethods, where it is used to cluster cells and most clusters
being only one cell. This rewrite uses a mesh wave to determine disconnected
regions in one go. This produced non-compact numbering which is then compacted
in a second phase.
On a 14M cell case with cyclic constraints this reduced decompose
time from 40 mins down to 5.

Before was zeroing displacement on all coupled points before
applying the displacement. This meant that we could not modify the
internal displacement on coupled points before setting the patch displacement.
Fixes #10.

- moved control to functionObject (from bc)
- this allows multi-region support
- see heatTransfer/chtMultiRegionFoam/externalCoupledMultiRegionHeater tut
- generalisation of streamed reading/writing of specialised bcs

- moved control to functionObject (from bc)
- this allows multi-region support
- see heatTransfer/chtMultiRegionFoam/externalCoupledMultiRegionHeater tut
- generalisation of streamed reading/writing of specialised bcs

- read nastran (NAS) surfaces in comma-separated free format

- bounds option (see $FOAM_UTILITIES/postProcessing/sampling/sample/sampleDict)
- fixes memory error http://www.openfoam.org/mantisbt/view.php?id=1487
- cleans up iso surface normal orientation

Updated objects
- corrected Peclet number for compressible cases
- propagated log flag and resultName across objects

New function objects
- new fluxSummary:
  - calculates positive, negative, absolute and net flux across face
    zones
- new runTimeControl
  - abort the calculation when a user-defined metric is achieved.
    Available options include:
    - average value remains unchanged wrt a given threshold
    - equation initial residual exceeds a threshold - useful to abort
      diverging cases
    - equation max iterations exceeds a threshold - useful to abort
      diverging cases
    - min/max of a function object value
    - min time step exceeds a threshold - useful to abort diverging
      cases
- new valueAverage:
  - average singular values from other function objects, e.g. Cd, Cl and
    Cm from the forceCoeffs function object

Also write out snapped location.

- user provides two planes and pressure drop across these
- bc assume potential flow and works out inlet velocity that would cause
an equivalent pressure drop

- user provides two planes and pressure drop across these
- bc assume potential flow and works out inlet velocity that would cause
an equivalent pressure drop

- checkMesh has option to write faceSets or (outside of) cellSets as
sampledSurface format. It automatically reconstructs the set on the master
and writes it to the postProcessing folder (as any sampledSurface). E.g.

    mpirun -np 6 checkMesh -allTopology -allGeometry -writeSets vtk -parallel

- fixed order writing of symmTensor in Ensight writers

- shm: have displacementMotionSolver as alternative mesh shrinker
  (instead of medialAxis).
- updated iglooWithFridges tutorial to use displacementLaplacian
- selectable interpolation from cells to points in the motion solvers
  using the 'interpolation' keyword:
    interpolation volPointInterpolation;    // default
    or
    interpolation patchCorrected (lowerWall upperWall);
- wrapped up mesh shrinkers (see above) for use as a displacementMotionSolver
  (i.e. the opposite of the displacementMotionSolver mesh shrinker)