added tagsearch API and frontend (TODO: intersect)
added /tags and /threads views
moved TagData to data.go
Revert "Temporarely remove limit for tags in home"

This reverts commit 2c5c3a4d0624eb76f4e4af17748e112ea93e2eb5.
Tag searches should be all lowercase
Moved View All links
Merge branch 'silverweed'