BugFix: fix the tagRelationhip so that a tag can be added to a visit item once
BugFix: fix bug so that when a tag is deleted, corresponding visiting items are updated
BugFix: now if we drag the interval to a tag. All items in the interval will be tagged
NewFeature: add functionality to delete tag of individual visiting items
New feature: add a more action button to DayView
Change CSS of more action button
Make data export and import function work with backbone structure
Remove some uncessary code from the repo
Make evernote update token work in the new code
Make evernote export functionality work for the new code based on backbone
BugFix: fix bug that after clicking the import option, view tag graph is broken