Make tag buttons in library views obey visibility setting
Added visible column to tags-overview
Added tag groups to allow some control over tag ordering (above alphanumeric)

git-svn-id: http://svn.vuze.com/public/client/trunk@40764 c2c1b7af-1477-405b-86ee-8aefd1fc4dd2
git-svn-id: http://svn.vuze.com/public/client/trunk@40766 c2c1b7af-1477-405b-86ee-8aefd1fc4dd2