Set mention notification as read when viewing post

  - If a mention for the current user and the displayed post exists,
    mark it as read
  - Use set_read_state instead of manually setting unread as false
Add test for mention notifications
Set sharing notification as read

  Fix issue #4951

  If the displayed user (on her profile) started sharing with the
current user, mark the notification as read
Fix hidding of poll publisher for close action
Merge pull request #5009 from taratatach/4951-sharing-notification-not-marked-as-read-when-visiting-profile

Set sharing notification as read
Merge pull request #5006 from taratatach/4940-mention-notification-not-marked-as-read-when-viewing-post

Set mention notification as read when viewing post
Merge pull request #5030 from hpetru/5029-hide-poll-input-after-post-submit

Fix hiding poll publisher for close action
Home page, registration page and robots.txt personnalization
Add my aspects link in the header
Add indication about testaccount and framasphere on the home page