Major changes:
  Add wrapper class AdaptiveGrid<Grid> to be used instead of a
    dune-grid within AMDiS. This provides most of the grid interface
    and supports automatic updates of bases.
  Change: MeshCreator now returns an AdaptiveGrid
  Change: ProblemStat uses AdaptiveGrid internally and returns an
    object of that type
  Add class ParallelGlobalBasis<Basis> as a replacement for a
    dune-functions basis. This implements the complete interface and
    can be used as a replacement for a regular basis in all contexts.
    It supports automatic updates.
  Add free function makeGlobalBasis to make a ParallelGlobalBasis
  Change: AMDiS basis creators now return a ParallelGlobalBasis
  Change: ProblemStat uses ParallelGlobalBasis internally and returns
    an object of that type
  Add classes Observer/Signals. Classes can derive from those to take
    part in the automatic update feature.
  Add update(Event const& e) methods to classes using the feature
    above. They implement the action to be done when the registered
    Event is triggered.
  Remove GridTransfer[-Manager] and replace with the new
    Observer/Signals implementation
  Change: linear algebra communicator is now a part of
    ParallelGlobalBasis
  Add wrapper for DataTransfer objects that can be used instead of a
    base class pointer and performs deep-copy operations on copy
    construction and assignment
  Change: DOFVector DataTransfer member is now stored using the new
    wrapper class DataTransferWrapper
  Change: preAdapt, adapt, postAdapt callbacks are now called after
    calling the respective grid function. Classes that previously used
    any of them had their methods changed accordingly.

Minor changes:
  Remove Comm argument for ctor of [Bi-]LinearForm, DOFVector
  Change ctor argument from Comm to Basis in
    linearalgebra/<impl>/[Matrix-, Vector-]Backend.hpp
  Simplify DOFVector copy/move by defaulting
  Remove DOFVector::resize override
  Remove DOFVectorInterface.hpp
  Change: linearalgebra/Traits.hpp includes the backend-specific
    Traits file. This is required to break an include loop.
  Add global 'solver category' initfile parameter used by the ISTL
    backend communicator when no parameter  at prefix + '->category'
    is found
  Fix commented out parts in DOFVectorTest, DiscreteFunctionTest
  Add unit test for Observer functionality
  Add helper function wrap_or_share (see amdis/common/SharedPtr.hpp)
  Fix backend = ISTL check for ISTLCommTest in CMakeLists

changed petsc cmake configuration

added computation of global DOF ids for pre-bases

Global basis ids for dune 2.6 and dune 2.7

corrected the unbind function

wrong unbind function call corrected

Added partition type query to GlobalIdSet

added documentation and extended the test

add general implementation and specialization for TaylorHoodBasis

corrected treepath of velocity component in taylorhoodbasis

add PETSc find module and configuration to cmake

add DofMapping for the association of local and global indices

changed petsc cmake configuration

added DOFMapping and test, to be used with petsc or pmtl backend

extension of istl preconditioner and amg precon

added block jacobi preconditioner with sequential sub precon

update ISTLCommTest for new Communication Creators

removed some smoothers due to bugs in dune-istl

added krylov AMG preconditioner

restructuring of istl solvers and preconditioners

Corrected errors in uniqueBorderPartitionTest and ProblemStat

changed default solver and removed solver category argument from precon creator

restructured stolver and precon creators in istl. Added precompiled explicit template instantiations.

cholmod for dune-2.7 only

removed explicit instantiation of AMG precons due to dune-istl bugs

Cleanup of AMG and more documentation, removed some precompiled preconditioner and solvers

redesign of linear algebra backend for inclusion of PETSc

petsc example added for study of the implementation

Matrix pattern communicates non-owning rows

petsc example extended for debugging

output of vectors does not use std::vector directly anymore

dirichletBC redesigned

restructuring of vectors and matrices, added BiLinearForm and LinearForm

cleanup of VectorBackend design. Needs to be applied to all backends!

adopt istl backend to changes in VectorBase and MatrixBase

Update CMakeLists and implemented twist of globalBasisIds

Communication in MatrixNnzStructure and DofMapping corrected.

not HAVE_MPI caseimplemented

do not use lv.maxSize() for mat and vec sizes

meshcreator with overlap and periodicity for YaspGrid

Twist indexing corrected and new UniqueBorderPartition strategy implemented, In MeshCreated the MAcroGridFactory removed, since it does not work in parallel

PETScCommTest added

MatrixNNZStructure extended to include remote dnnz numbers

made all backends conforming to the new structure

MeshCreator now reads AlbertaGrid only on rank 0

make vector copyable

export BACKEND cmake flag to amdis-config file

cmake-pkg config file added

pkg config file updated and PETSc direct solver added

update MTL and PETSc backend after complex test

make petsc constraints work on DirichletNodes that are not on boundary intersections

moved AMDIS_INFO_LEVEL to Output

updated the backup-restore test and corrected some small errors

make friend use struct instead of class for Constraints

change solver parameter in generated initfile of amdisproject and add PETSc to README

update choldmod to recent dune version