multiphaseInterFoam: changed alphaContactAngleFvPatchScalarField to multiphaseAlphaContactAngleFvPatchScalarField

to avoid name clashed with the version of alphaContactAngleFvPatchScalarField in the interfaceProperties library.

Relaxation and solution parameters for the final iteration in PIMPLE loops are
now selected according to the value of the "finalIteration" entry in the
mesh::data dictionary.

rhoPimpleFoam significantly updates and now replaces rhoPisoFoam.

This reverts commit c600ce54.

- fix 'forAll (' -> 'forAll(' format (again)

- both versions handle the same input words.
  Only need the <Switch> version when the destination variable is
  also a Switch and we need to output the word later.

- add const-ness for control variables

- drop unused fluxGradp variable

- use lookupOrDefault instead of found/lookup combination

before:
    - 'new' prefixed to camel-cased class name: eg, someClass -> newSomeClass
    - 'New' prefixed to templated class name:   eg, TmplClass -> NewTmplClass
    - 'New' suffixed to class name:             eg, someClass -> someClassNew

after:
    - consistent 'New' suffixed to class name, no change of case
          eg, someClass -> someClassNew
          eg, TmplClass -> TmplClassNew

- accept some violations of the coding guidelines though
- perhaps adding a style exception would be simpler.

- remove epsilonSmall, omegaSmall
- k0/epsilon0/omega0 become kMin/epsilonMin/omegaMin
- add qMin/zetaMin for consistency

These files still need some attention:
    dynOneEqEddy.C
    NonlinearKEShih.C
    settlingFoam

BUG: incompressible::LESModels:dynOneEqEddy::correct()
- avoid tmp field destruction for consistency with the compressible
  version

Possible TODO:
   - set kMin to zero (instead of SMALL) and introduce kSmall
     to avoid division by zero

Added compressibility support to MRFZone.
Required generalisation of the oneField concept.
Also clean-up the use of one and zero for consistency.
Simple mixerVessel2D tutorial case supplied.

While p and pmh (pd in OpenFOAM-1.5.?) are equivalent on orthogonal meshes they
are not on non-orthogonal meshes and the difference is very important for
buoyancy-dominated flows such as settling.  settlingFoam is now written in terms
of pmh (static pressure minus hydrostatic pressure) which used to be called pd
but that confused too may people.

- to match coding guidelines

- space between keyword and bracket in 'for(..)', 'if(..)', 'while(..)'

- markup codingStyleGuide.org examples so they actually indent correctly

- use 'Info<<' as per codingStyleGuide instead of 'Info <<'

with the boundary motion before the fluxes are corrected for continuity by
pcorr.

    deltaT().value() to deltaTValue()
and
    deltaT0().value() to deltaT0Value()
across the whole code - faster to return especially if being used
often, in each call to a submodel for example.

the include file back to mathematicalConstants.H to make upgrading code slightly easier.

This reverts commit 54a8b6a1.

- this would be an argument for providing default values at the top-level
  compressible/incompressible turbulenceModel