to avoid file names which are two long for the standard GNU/Linux file systems.

A simple 'sleep' is more reliable.

Patch contributed by Mattijs Janssens
Resolves bug-report http://bugs.openfoam.org/view.php?id=2143

then synchronize the file system to ensure all links are flushed before
compilation starts

for consistency with HeatAndMassTransferPhaseSystem.C
Resolves bug-report http://bugs.openfoam.org/view.php?id=2141

Uses the 'wait -n' builtin to avoid the use of non-POSIX 'sleep' commands

Based of patch contributed by Francesco Contino, Tommaso Lucchini,
Gianluca D’Errico, Hervé Jeanmart, Nicolas Bourgeois and Stéphane
Backaert.

e.g. to avoid excessive unphysical velocities generated during slamming events in
incompressible VoF simulations

Usage
    Example usage:
    limitU
    {
        type            limitVelocity;
        active          yes;

        limitVelocityCoeffs
        {
            selectionMode   all;
            max             100;
        }
    }

Contributed by Alberto Passalacqua, Iowa State University

Foam::dragModels::Beetstra
    Drag model of Beetstra et al. for monodisperse gas-particle flows obtained
    with direct numerical simulations with the Lattice-Boltzmann method and
    accounting for the effect of particle ensembles.

    Reference:
    \verbatim
        Beetstra, R., van der Hoef, M. A., & Kuipers, J. a. M. (2007).
        Drag force of intermediate Reynolds number flow past mono- and
        bidisperse arrays of spheres.
        AIChE Journal, 53(2), 489–501.
    \endverbatim

Foam::dragModels::Tenneti
    Drag model of Tenneti et al. for monodisperse gas-particle flows obtained
    with particle-resolved direct numerical simulations and accounting for the
    effect of particle ensembles.

    Reference:
    \verbatim
        Tenneti, S., Garg, R., & Subramaniam, S. (2011).
        Drag law for monodisperse gas–solid systems using particle-resolved
        direct numerical simulation of flow past fixed assemblies of spheres.
        International Journal of Multiphase Flow, 37(9), 1072–1092.
    \verbatim

Patch contributed by Mattijs Janssens

Ensures the order of compilation relates to the location of the source files

and added support for queue scheduling option '-q', '-queue'

Now the 'Allwmake' scripts execute 'wmake -all' to handle parallel
processing in a general way, avoiding code duplication.

It is better to run doc/Allwmake or doc/Doxygen/Allwmake and provide the
required options.

Patch contributed by Bruno Santos
Resolves bug-report http://bugs.openfoam.org/view.php?id=2138

wmakeCollect collects the compilation commands for the all of the object
files to be compiled into a single makefile which is passed to make to
schedule the compilations in parallel efficiently.

Before wmakeCollect can be called the lnInclude directories must be
up-to-date and after wmakeCollect the linkage stage of the compilation
must executed using wmake.

This entire process is now handled by wmake using the new '-queue' or
'-q' option to compile sections of the OpenFOAM source tree or the
entire tree efficiently.  The number of cores the compilation executes
on may be specified either using the WM_NCOMPPROCS variable or the '-j'
option.

To efficiently compile OpenFOAM after a 'git pull' the '-update' option
is provided which updates lnInclude directories, dep files and removes
deprecated files and directories.  This option may be used with '-q':

    wmake -q -update