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.
Documentation: Remove references to svn

Remove references to svn's $Id$ in the headers and replace references to
the old subversion repository in various html files
Documentation: Remove bogus indentation.html file

Well, we already have a detailed doxygen file about indentation. So it is
better to add the three relevant lines about astyle there and remove this
additional documentation page completely
Documentation: Remove svn.html from offline documentation

The new development guidelines for git should be prominently on the
homepage, not buried in the offlinedocumentaiton. So just remove the old
cruft.
Documentation: Remove all references to external resources

We already link to this  external resources on the homepage - there is no
point in doing it here (nobody will find it and it has the bad tendency of
being out of date).
Documentation: also cleanup toplevel TOC

Remove all external references and stale content from the toplevel
documentation TOC
Documentation: remove stale html files

The news items up to 2003 are not used on the homepage anymore - and also
not incorporated in doxygen - so remove them.

Also remove the news.html and publications/indexl.html stubs - they are not
referenced any more.