Merge develop into master for v1706 release

Closes #505, #509, #497, #502, #500, #498, #493, #492, #490, #485, #486, #484, #481, #480, #467, #473, #470, #466, #464, #463, #460, #462, #458, #418, #420, #391, #452, #454, #453, #439, #427, #415, #422, #414, #411, #400, #398, and #348

See merge request !121

STY: Fixing syntax in rhoPimpleDyMFoam/pEqn.H

by fvMesh.writeObject().

- end user can easily see which arch (endian, label/scalar size) was
  used from the log output, or via -help usage

- this is the same version as OpenFOAM-1612 shipped with and seems to
  have fewer issues than the newer openmpi-2.1.1

Feature rho pimple adiabatic

See merge request !118

Solver for low Mach no. flows with adiabatic thermodynamics and updated
pressure-velocity coupling given by the RCM interpolation procedure
described in

    \verbatim
        Knacke, T. (2013).
        Potential effects of Rhie & Chow type interpolations in airframe
        noise simulations. In: Schram, C., Dénos, R., Lecomte E. (ed):
        Accurate and efficient aeroacoustic prediction approaches for
        airframe noise, VKI LS 2013-03.
    \endverbatim

Original code supplied by Thilo Knacke, CFD E+F GmbH
contact: info@cfd-berlin.com

Integrated into OpenFOAM by OpenCFD Ltd.