Merge pull request #55 from cuongnv540/task#5420

fix unable to delete poll
Task #5423 Change poll index view
Merge pull request #58 from wataridori/task/5423

Task #5423 Change poll index view
Task#5434 get all poll that a user can see
Merge pull request #59 from vigov5/task#5434

Task#5434 get all poll that a user can see
Task#5466 create activity table
Merge pull request #61 from vigov5/task#5466

Task#5466 create activity table
fix error on display poll
Task#5468 create activity model
Merge pull request #62 from vigov5/task#5468

Task#5468 create activity model
Task #5422 delete/validate choice, only owner can add choice
Task #5464 Create ViewLink Behavior and attach it to models
Merge pull request #64 from VanGiang/task/5422

Task #5422 delete/validate choice, only owner can add choice
Merge pull request #63 from wataridori/task/5464

Task #5464 Create ViewLink Behavior and attach it to models
Merge pull request #60 from thaipt1012/task#5462

fix error on display poll
fix delete all poll and comment when delete user
Merge pull request #65 from huyen123/task#5465

fix delete all poll and comment when delete user
Bug #5470 fix link add choice page
Merge pull request #66 from VanGiang/task/5470

Bug #5470 fix link add choice page
Bug#5458 Fix update and create poll time