Implemented client-side review support
Fixed preferences strings
Merged with 'next' branch to include mute button
Merge to release 0.8.4
Added lessons notifications and URL preferences
Implemented lessons notify behaviour
Added search window
Completed basic search functionality
Fixed bug causing NPEs on kaji without on'yomi or kun'yomi
Merge branch 'next' into clientside
If URL is unset, default to current Wanikani URL
Added search button behaviour
Merge branch 'next' into clientside