have the full set of methods as the higher-dimensional geometries.

It would be possible to provide default implementations for the new
dim=0 methods in the wrapper class.  This would not lead to any
efficiency problems, as any if(mydim==0) can get optimized away.
However, the different grid implementations still need to have
the functions in order to have the code compile.  So for now I
didn't include default implementations.

[[Imported from SVN: r4079]]

[[Imported from SVN: r4078]]

[[Imported from SVN: r4077]]

[[Imported from SVN: r4076]]

[[Imported from SVN: r4060]]

only UGGrid supports grids with more than one element type.

[[Imported from SVN: r4059]]

the index disregards the GeometryType.  That is, indices are consecutive
and zero-starting in one set.  This is usefull for element or face data
on grids with more than one element type.

You can instantiate a PanTypeIndexSet by given it a Level- or LeafIndexSet.

[[Imported from SVN: r4058]]

Move the two images used by doxygen there.

[[Imported from SVN: r4051]]

[[Imported from SVN: r4036]]

[[Imported from SVN: r4035]]

[[Imported from SVN: r4030]]

Check the consistency of numberInSelf, numberInNeighbor and the indices and ids of the subface between.

[[Imported from SVN: r4028]]

[[Imported from SVN: r4027]]

always returns 1.  This fixes a bug in the SGrid<1,1> test.

[[Imported from SVN: r4026]]

- Test SGrid<1,1>
- Test SGrid<4,4>

[[Imported from SVN: r4025]]

Real implementation for UGGridGeometry<1,2>::local()

[[Imported from SVN: r4024]]

- try to get IntersectionNeighborLocal only if there is a neighbor
- compute the intersection vertex center correctly

[[Imported from SVN: r4023]]

[[Imported from SVN: r4022]]

[[Imported from SVN: r4021]]

work to do.

[[Imported from SVN: r4020]]

[[Imported from SVN: r4019]]

[[Imported from SVN: r4018]]

[[Imported from SVN: r4017]]

[[Imported from SVN: r4016]]

[[Imported from SVN: r4015]]

[[Imported from SVN: r4014]]

[[Imported from SVN: r4013]]

[[Imported from SVN: r4011]]

[[Imported from SVN: r4010]]

[[Imported from SVN: r4009]]

[[Imported from SVN: r4008]]

[[Imported from SVN: r4007]]

[[Imported from SVN: r4006]]

[[Imported from SVN: r4005]]

leaf elements (the UG-equivalent fullRefineLevel cannot be used because
apparently it's only computed when you're using UG algebra).  The
leaf iterator uses this information and has to traverse less grid
elements.  This speeds up leaf traversal by about 10% in 3d, I suspect
it should be about 20% in 2d.

[[Imported from SVN: r4004]]

Add renumbering of faces from UG to DUNE.

[[Imported from SVN: r4003]]

[[Imported from SVN: r4002]]

[[Imported from SVN: r4001]]

[[Imported from SVN: r3998]]

[[Imported from SVN: r3993]]