Augment documentation.

The documentation of MultithreadInfo was unintelligible. It was also
incomplete in some places.
Remove #includes of multithread_info.h in files that don't need it.
Merge pull request #5 from bangerth/doc-fixes

Augment documentation.

The documentation of MultithreadInfo was unintelligible. It was also
incomplete in some places.
Merge pull request #6 from bangerth/remove-multithread_info.h-includes

Remove #includes of multithread_info.h in files that don't need it.
Fix style issue.
Joint work with Arezou Ghesmati: Add GridTools::get_patch_around_cell().
Provide attribution.
Add some documentation.
Merge pull request #8 from bangerth/add-patch-generators

Add GridTools::get_patch_around_cell().

Implement a function GridTools::get_patch_around_cell() extracts the
set of cells that surround a single cell. This is joint work with
Arezou Ghesmati.
Update documentation of this file.

- Rename a documentation section to be more descriptive.
- Reshuffle some more functions and group them into appropriate categories. Not all functions are in categories yet, though, see http://www.dealii.org/developer/doxygen/deal.II/namespaceDoFTools.html
compatibility fixes for p4est 1.0

The deprecated type p4est_connect_type_t got removed in p4est >=1.0. Use
connect_type_t instead.
p4est-setup.sh can now also build from source directory
Merge pull request #11 from tjhei/p4est_script

[minor] p4est-setup.sh can now also build from source directory
Merge pull request #10 from tjhei/p4est_update

[minor] compatibility fixes for p4est 1.0
Merge pull request #9 from bangerth/doc-fixes

Update documentation in include/deal.II/dofs/dof_tools.h

- Rename a documentation section to be more descriptive.
- Reshuffle some more functions and group them into appropriate categories. Not all functions are in categories yet, though, see http://www.dealii.org/developer/doxygen/deal.II/namespaceDoFTools.html
Rewrite the documentation of DoFTools::compute_intergrid_constraints().

The previous version of the documentation basically stated why the function exists, not what it does. This is the focus of the new version. I also indented the arguments of this function and the (related) following one.
CMake: robust version extraction for P4Est

Make the version extraction in P4Est more robust: We should not rely on
the version string to define SUBMINOR and PATCH - this doesn't have to
be the case. So, always set P4EST_VERSION_SUBMINOR and
P4EST_VERSION_PATCH to "0" in FindP4EST.cmake if no valid number could
be extracted.
Introduce the concept of containers-of-cells and link to it in various places.
Add some description of when the last two IFs can happen in version
number recognition.
Merge pull request #17 from bangerth/fix_p4est_configuration

Fix p4est configuration