LB-819: On timeline all posts are 2h before CET

Use dust userdate helper for timeline dates.
LB-917: Hide take offline/go online button on admin interface

Remove the button and make dashboard user open/closed status for
filtering.
LB-843: When chained blog source is shown one of chained blogs should be selected

Fixed selecting blog issue with changing chained blogs.
Merge pull request #292 from petrjasek/lb-917-rm-offline-button

Lb 917 rm offline button
Merge pull request #261 from petrjasek/lb-819-timeline-dates

Lb 819 timeline dates
Merge pull request #294 from eozan/LB-843

Lb 843