Interface and time loop changes. Processes are in the
next commit.

This is going to replace one part of the local_coupled_solutions
object.

Pass through the interface to avoid the coupled_xs
in the feature.

Pass process_id to FEM::assemble calls.

Drop dt where used together with it's updates etc.

Exemplary on SmallDeformationProcess, storage of dt
is no longer required and the assembly can be repeated
without dependency on the t/dt values.

With this it becomes possible to use the t/dt values
directly instead of storing them in *ProcessData
and retrieving at later point.

Fixes multiple copyright messages in the doxygen docu.

ag '\\file' -L --ignore=ThirdParty *Lib |xargs  sed -i 's/\(.*\)\\copyright/\1\\file\n\1\\copyright/'

Some of the local assembler initialization cannot
be done in its constructor but after initial conditions
have been set. This function allows such initialization
procedures.

Some processes might require setup of the initial
conditions dependent variables in local assemblers.
The new interface allows such implementations.

 for the staggered coupling scheme

about getting the local solutions of an element.

Clang format run on near-the-header lines.

Happy New Year

 from the two classes of coupled term.

[Coupling] Changed the members of the coupled term,

 which only contains the solutions of the coupled equations.

pointer to StaggeredCouplingTerm

 coupled processes.

 for the staggered scheme.

See also "[PL] moved index computation to local assembler interface"
2d891b06 .