#250 imporve vanity profile url performance
uesd authorization management in events controller with cancan
add test code about authorization management with event
delete some method in event controller because they are no used
change some test code because event controller used `cancan` now
slug should not conflict with routes.
Merge pull request #253 from xiaods/feature/250-refine-vanity-profile-url

 #250 imporve vanity profile url performance
Merge branch 'issues_245' of git://github.com/ywjno/19wu into ywjno-issues_245
use cancan to check user ablity. close #245
Merge pull request #256 from ywjno/issues_245

issues_245_uesd_cancan
use &&, || instead of and, or
revert some change.
Merge branch 'master' into saberma-enhancement/256-use-cancan-to-check-ablity
Merge pull request #257 from saberma/saberma-enhancement/250-slug-should-not-conflict-with-routes

活动和用户的短链接地址不能是路由表中已有的规则名称