Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=2059

Old:
- Previous versions created k and epsilon fields by default, and
  then processed omega and nuTilda fields if present.
- Depending on the choice of turbulence model, not all of these fields
  would be used, and could lead to errors when running some utilities
  due to erroneous values.
- If the omega field did not exist, it would be derived from the epsilon
  field, and also inherit the epsilon boundary conditions (wall
  functions)

New:
- This version will only update fields that already exist on file, i.e.
  will not generate any new fields, and will preserve the boundary
  conditions

Fixes #103

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.

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.

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.

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

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

e.g. (fvc::interpolate(HbyA) & mesh.Sf()) -> fvc::flux(HbyA)

This removes the need to create an intermediate face-vector field when
computing fluxes which is more efficient, reduces the peak storage and
improved cache coherency in addition to providing a simpler and cleaner
API.

applications/test/rigidBodyDynamics/pendulum: Simplified using sphere constructor and body lookup by name

Patch contributed by Bruno Santos
Resolved bug-report http://www.openfoam.org/mantisbt/view.php?id=2042

applications/test/rigidBodyDynamics/pendulum: Very simple test/demonstration of the rigidBodyDynamics library

    Simple swinging pendulum simulation with 1-DoF.  The motion is integrated
    using a symplectic method for just over 2-periods.

    //- Disallow default shallow-copy assignment
    //
    //  Assignment of UList<T> may need to be either shallow (copy pointer)
    //  or deep (copy elements) depending on context or the particular type
    //  of list derived from UList and it is confusing and prone to error
    //  for the default assignment to be either.  The solution is to
    //  disallow default assignment and provide separate 'shallowCopy' and
    //  'deepCopy' member functions.
    void operator=(const UList<T>&) = delete;

    //- Copy the pointer held by the given UList.
    inline void shallowCopy(const UList<T>&);

    //- Copy elements of the given UList.
    void deepCopy(const UList<T>&);