#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
list, add and destroy collaborators.
collaborator can create and update event.
use cancan ability.
move baidu map to the sidebar.
Merge branch 'issue#347' of github.com:loveky/19wu into loveky-issue#347
fix typo.
Merge pull request #367 from saberma/saberma-enhancement/363-move-baidu-map-to-right-bar

编辑活动页面的百度地图移到右边栏
fixed: collaborator modify event error.
only event group creator can manage collaborators.
fixed: loop redirector error.
authorize event for participants controller.
add collaborator feature test.
fixed rspec error.