Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1658

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1638

mixtureKEpsilon: Changed bounded non-conservative transport flux to be volumetric rather than mass-based
Avoids numerical problems caused by large density gradients, particularly around the interface.
Allows the use of higher-order differencing for km and epsilonm

Added the pressure dependent part of the entropy from the equation of
state to that returned by the thermo entropy function.

TODO: Add entropy defect to the PengRobinsonGas::s(p, T) function.

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1411

The implementation now correspond to the definitions in the readily
available reference:

http://personalpages.manchester.ac.uk/staff/david.d.apsley/specturb.pdf

in which a large number of linear and non-linear models are presented in
a clean and consistent manner.  This has made re-implementation and
checking far easier than working from the original references which anyway
are no longer available for the LienCubicKE and ShihQuadraticKE models.

Also use the innerSqr function where appropriate

Needed to create generic compressible turbulence model library

    Egorov, Y., & Menter F.R. (2008).
    Development and Application of SST-SAS Model in the DESIDER Project.
    Advances in Hybrid RANS-LES Modelling,
    Notes on Num. Fluid Mech. And Multidisciplinary Design,
    Volume 97, 261-270.

turbulenceModels/LES/dynamicLagrangian: Added the Lagrangian averaged form of the dynamic Smagorinsky eddy-viscosity SGS model for LES

Also moved global classes which should be in the Foam namespace into it.

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1514

turbulenceModels/RAS/SSG: Added Speziale, Sarkar and Gatski pressure-strain based Reynolds-stress turbulence model

classes in the DebugSwitches sub-dictionary of system/controlDict