added: OpenMP support
added: allow switching between fastamg and amg through template param
changed: use the dynmatrix helpers from upstream (now in dune-common)
added: checker-board uniform mesh if given a rocklist with > 1 materials

useful for tests
fixed: specifying the global dimensions of a uniform mesh
added: ability to use overlapping schwarz as a smoother
changed: drop seqlu in favor of new upstream template InverseOperator2Preconditioner
added: allow switching AMG smoothers from commandline
modernize pointer handling

use shared_ptr instead of manual delete's
utilize the preprocessor to keep template boilerplating at acceptable levels
added a bunch of useful debugging options
support dune's two level preconditioner
allow using a different preconditioner for the multiplier block