Tagging mockup and new popup with tagging function
Tracking and styling for popup
Keep track of all tags in tags key
Wire up tag interface and bahavior in History
remove unneeded permissions
Move all tag persistence into separate class

fixes #127
rename tags, first pass

fixes #128
drop and drag history visits to tag them

fixes #130
popup UI improvements
redirect to all tags page on tag delete
Merge tags if new tag exists during rename
Drop collections in favor of tgas in code
Show tags on each visit
fade out after tagging visit
tags list redesign
configure click behavior on tags
Shortcut for browser action
Add example tags
tagging instructions
fix how to tag link in about tags