Added timeline ATOM feed and removed XHTML target
* moved repository feeds to `repository` directory
* replaced paginated XHTML timeline target with and ATOM feed
** removed `paginated_timeline.xsl` transformation including the `04_meta` level
** removed CSS and master stylesheets
* added title, url and commit count meta data to `meta.xml`
* expanded ATOM feed URLs
* timeline feed has an upper limit of `commit_count` items
** repository feeds have the same limit because only `commit_count` commits of every repository are fetched in the first place