Tightening up some spacing

- allow for a .small Card variation: limited tags/meta, listed next to
the .title
- tighten up spacing between tags
- remove .pagination bottom padding (there's padding on the pagination
links)
- tighten up horizontal spacing on menu items
- reduce horizontal padding on slat items
- fix an issue with Bartender that could result in (apparent) duplicate
menu items. _.trim() all the things!
- In prospectus, less verbose method to make sure you end up in the
right place in the tab order and can't tab into the active bar
- Added a check to keep aria-activedescendant from moving around via
mouse hover if you're actively focused on a menu item, which also helps
make sure a menu only ever takes up one tab stop
- add (hidden) "Common" tags to Core 3 sub-specs
- RDF workgroup is "RDF Data Shapes"

Related to issue #9