refonte de l'appli d'admin

[Tomo59]

• do 4 separated "folders"

1. liveness
2. messages
3. checkpoint error
4. alerts

• use bootstrap & angular
• regarding errors (most important part)

1. display 2 views
   1. one sorted by site
   2. one sorted by timestamp
2. improve insertion of time
3. improve view of times (maybe remove day)