NR-887 : Article-> Add files from Media Archive - GUI issues

Fixed
NR-977 : Main Navigation concept for Superdesk

CSS done
Buttons styling

Shadow fix
LB-689 : Styling for comments as a content source

Fixed
LB-690 : FF browser -> Longer SMS text without spaces is not rendered well in timeline

Fixed
Merge pull request #36 from nidzix/nr-893-media-archive-CSS-fix

CSS update for several tasks:
	 NR-887 : Article-> Add files from Media Archive - GUI issues
	 NR-977 : Main Navigation concept for Superdesk
	 Buttons styling
	 LB-689 : Styling for comments as a content source
	 LB-690 : FF browser -> Longer SMS text without spaces is not rendered