rigidBodyMeshMotion: displacementMotionSolver for the mesh-motion of multiple articulated rigid-bodies

The motion of the bodies is integrated using the rigidBodyDynamics
library with joints, restraints and external forces.

The mesh-motion is interpolated using septernion averaging.

This development is sponsored by Carnegie Wave Energy Ltd.

Using method based on
http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20070017872.pdf
but simplified for the case where the quaternions are similar.

Patch contributed by Bruno Santos
Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=2055

Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=2053

Patch contributed by Bruno Santos

inline Foam::vector Foam::septernion::transformPoint(const vector& v) const
{
    return r().transform(v - t());
}

Now there is a 1:1 correspondence between septernion and
spatialTransform and a septernion constructor from spatialTransform
provided.

Additionally "septernion::transform" has been renamed
"septernion::transformPoint" to clarify that it transforms coordinate
points rather than displacements or other relative vectors.

Replaced with 'unitQuaterion()' virtual function to indicate if the
joint uses a unit quaternion to represent rotation.

rigidBodyDynamics: Simplify handling of quaternions by maintaining a unit quaternion in the joint state field 'q'

'w' is now obtained from 'v' using the relation w = sqrt(1 - |sqr(v)|)
and 'v' is stored in the joint state field 'q' and integrated in the
usual manner but corrected using quaternion transformations.

    //- Return the unit quaternion (versor) from the given vector
    //  (w = sqrt(1 - |sqr(v)|))
    static inline quaternion unit(const vector& v);

rigidBodyDynamics/rigidBodySolvers: Added run-time selectable solvers to integrate the rigid-body motion

Currently supported solvers: symplectic, Newmark, CrankNicolson

The symplectic solver should only be used if iteration over the forces
and body-motion is not required.  Newmark and CrankNicolson both require
iteration to provide 2nd-order behavior.

See applications/test/rigidBodyDynamics/spring for an example of the
application of the Newmark solver.

This development is sponsored by Carnegie Wave Energy Ltd.

“Error when reading ascii data. Possible mismatch of datasize with
declaration.”

Patch contributed by Karl Meredith, FMGlobal

This is a more convenient way of maintaining the state or multiple
states (for higher-order integration), storing, retrieving and passing
between processors.

Included for backward-compatibility with the 6-DoF solver but in the
future will be re-implemented as a joint rather than body restraint and
accumulated in tau (internal forces) rather than fx (external forces).

applications/test/rigidBodyDynamics/spring: Test of the linear spring with damper restraint
Damped simple harmonic motion of a weight on a spring is simulated and
the results compared with analytical solution

    Test-spring
    gnuplot spring.gnuplot
    evince spring.eps

This development is sponsored by Carnegie Wave Energy Ltd.

rigidBodyDynamics/bodies/subBody: Changed "parent" to "master" to avoid confusion with the parent to which this composite body is joined

Added support for composite joints including a specialized 6-DoF form for floating bodies.

rigidBodyDynamics/bodies: Complete set of clone functions to support copy construction and assignment