[[Imported from SVN: r3654]]

1) Generation of sparse matrix
2) Assembling of global stiffness matrix from local stiffness matrices
3) Interface for providing a local stiffness matrix and boundary conditions

All this is only for P1, but it works with hanging nodes, in parallel (with
algebraic extension of nonoverlapping grids) and for systems.
(Systems are yet untested).

[[Imported from SVN: r3653]]

[[Imported from SVN: r3652]]

that seperates it in a local (elemenwise) part and a global part

[[Imported from SVN: r3651]]

matrix row.

Compiles again and works for the sequential case.

[[Imported from SVN: r3650]]

[[Imported from SVN: r3649]]

[[Imported from SVN: r3648]]

[[Imported from SVN: r3647]]

[[Imported from SVN: r3646]]

method insertLinearSegment() is now private, as it is not supposed to be used from the outside any more

[[Imported from SVN: r3645]]

[[Imported from SVN: r3644]]

[[Imported from SVN: r3643]]

[[Imported from SVN: r3642]]

Cannot anybody test this definitely on a machine that has no MPI. I
simulated it by setting HAVE_MPI to false.

[[Imported from SVN: r3641]]

[[Imported from SVN: r3640]]

[[Imported from SVN: r3639]]

... well now my lib builds again and the test works aswell

... hope that's all ...

[[Imported from SVN: r3638]]

[[Imported from SVN: r3637]]

[[Imported from SVN: r3636]]

[[Imported from SVN: r3635]]

[[Imported from SVN: r3634]]

This is needed as one wants to setup only those indices involved in
the  communication.

First step in making AMG work with those smaller index sets.

[[Imported from SVN: r3633]]

changed include

[[Imported from SVN: r3632]]

renamed file

[[Imported from SVN: r3631]]

P1FEFunction can be compiled without having MPI again.

[[Imported from SVN: r3630]]

[[Imported from SVN: r3629]]

[[Imported from SVN: r3628]]

[[Imported from SVN: r3627]]

signed/unsigned comparison

[[Imported from SVN: r3626]]

Testing still pending.

[[Imported from SVN: r3625]]

[[Imported from SVN: r3624]]

[[Imported from SVN: r3623]]

[[Imported from SVN: r3622]]

[[Imported from SVN: r3621]]

missing.

[[Imported from SVN: r3620]]

[[Imported from SVN: r3619]]

[[Imported from SVN: r3618]]

[[Imported from SVN: r3617]]

[[Imported from SVN: r3616]]

[[Imported from SVN: r3615]]