Tooltip for lock icon + starts in unlocked mode
Tooltip wording fix
Syncs locking state of all realm windows
remembers locking state between sessions, separately for each document

https://app.asana.com/0/15028213105325/16105342773907
Merge branch 'master' of http://github.com/Realm/realm-cocoa into gk-browser-fix-lock-icon
Fixes for JPs comments
Merge pull request #893 from GreatApe/gk-browser-fix-lock-icon

Gk browser fix lock icon