Import those parts of BOOST 1.56.0 that we need for deal.II.

This includes renaming the existing directory and overwriting every
file with the corresponding one from BOOST 1.56.0. Then removing thos
parts of the boost sublibraries that we don't need but that for
some reasons were included previously. Specifically, this applies to
documentation and build directories in libs/ and to the fusion and
spirit libraries that consist exclusively of header files.
Update test output.
Adapt a patch from around the internet to fix an issue with gcc 4.6.
Add a default value for spacedim.

This matches all other existing places where we have both
'dim' and 'spacedim' as template arguments.
Merge pull request #114 from bangerth/fix-default-template-argument

Add a default value for spacedim.

This matches all other existing places where we have both
'dim' and 'spacedim' as template arguments.
Merge pull request #107 from bangerth/update-boost

This is a patch to update boost to the latest version, 1.56.0.
Add documentation to the manifold module.

In particular, give an example of why it matters and a few code snippets and pictures
that show how it works.
Provide a link to the manifold documentation module.

Also provide more discussion and fix a number of oversights in the
current version of the documentation.
Add another cross reference.
Merge pull request #115 from bangerth/more-manifold-documentation

More manifold documentation
indent with astyle
Merge pull request #91 from tjhei/pr_astyle

indent with astyle
Add back the spirit sublibrary of boost.

We apparently need it from the serialization sublibrary.
Add forgotten header file.
Merge pull request #116 from bangerth/add-missing-spirit-lib

Add back the spirit sublibrary of boost.
Only test indentation on pull requests.
Merge pull request #117 from luca-heltai/travis_ci_indent_check

Only test indentation on pull requests. This closes issue #89, where we discussed about possibly testing with Travis CI the indentation of the pull request.

Since most of the pull requests are failing anyway on Travis (time limit for a pull request is 25 minutes, and we hit it pretty regularly), this pull request configures Travis CI to only check indentation in pull requests, and do the full build only when the pull request is merged on master.
Removed all builds. Only indent test.
Moved download and install of astyle into before_install section. Renamed files.
Merge pull request #118 from luca-heltai/fix_travis_ci

Removed all builds. Only indent test.

I implemented here Matthias' suggestion. Removing all unnecessary comments and lines from the Travis CI configuration scripts. This should also make it much faster, since we don't need to install anything anymore (except astyle). This is the one that closes #89.