DOCS: add a doc about view hierarchy.
test: add GlobalSettings for test
NotiEvent: notifying commits that have been pushed
Notification: new commits with branch name
Notification: Added url test
Merge branch `enhancement/test` of kjkmadness/yobi

from pull request 352
Merge branch `noti/push` of whiteship/yobi

from pull request 354
Merge branch `technical-viewHierarchy` of changsung/yobi

from pull request 326
refactoring: PostReceiveHook
fix broken tests
CSS:exchange css resource path to relative path from aboluste path
Merge branch `refactoring/post-receive-hook` of kjkmadness/yobi

from pull request 358
Merge branch `issue/css-image-path` of insanehong/hive

from pull request 394
pullRequest: improve PullRequestEventActor

1. separate PullRequestMergingActor, RelatedPullRequestMergingActor
2. using PullRequestMergingActor at regist pullRequest and reopen
pullRequest
3. using RelatedPullReuqestMergingActor at pushed code and merged
pullRequest
4. add pullRequest property in PullRequestEventMessage
pullRequest: fix edit form error
Merge branch `improve/pullrequest` of alecsiel/yobi

from pull request 393
notification: change the message for pushed commits.
pullrequest: fix 'mergedCommitIdTo' appropriately
pullrequest: add alternate object direcotry
Main: add new commit event icon of Notification