Removed remnants of layout iteration and cleaned CSS
* both the CSS and master template markup contained cruft from the previous blog version and its slightly different layout
* removed unnecessary distinction between footer and its _taglist_ as the old footer element is now only a _taglist_
** promoted previous `last_line` to `footer` as it is the actual footer
* unified the different list styles as much as possible
** e.g. introduced new `topline` attribute instead of declaring the title-separator line for each style separately
** removed `taglist` class by declaring its rules directly in the `tags` id
** removed now unnecessary `archivtag` class
** introduced `sparselist` class which enables list such as the one contained the latest microblog entries to have extra padding
* merged `list_tags` helper template into primary master template
** this separation was not only unnecessary but decreased the readability as it provided no real encapsulation