Fix link in step-52
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being out of date).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: remove stale html files

Remove news.html and publications/indexl.html stubs - they are not
referenced any more.
clenaup toc, remove stale information
put license.html directly on the homepage
Merge pull request #367 from tamiko/fix_documentation

Update documentation