#347 add EventSummary model
#347 add ability to create/update event summary
#347 add event summary page link to menu
#349 show event summary on event show page
#347 add feature test
#349 show previous event summary on a unfinished event page
#347 Modify LOC spec, only counting Ruby&JS code now
Merge branch 'issue#347' of github.com:loveky/19wu into loveky-issue#347
fix typo.