Implemented first version of a slidable navigation bar.
Merge branch 'master' into feature-slidingnavigation-mab-master

Conflicts:
	Kernel/Output/HTML/Standard/AgentNavigationBar.dtl
	var/httpd/htdocs/skins/Agent/default/css/Core.Header.css
Replaced characters by font awesome icons.
Tidied.
Fixed: Dashbord: Widget DefaultColumns is not working (bug#10211).
Fixed: Move mask in new window: Note is not required (bug#6742).
Fixed: GenericAgent - Ticket-Action should be renamed to Ticket-Attribute (bug#6671).
Fixed: My tickets & Company tickets in 3.3.4 (bug#10212).
Updated Polsih translation
Fixed bug#4512 - HTMLUtils ToAscii forces line breake on fixed line-length 78.
Follow-up fix for bug#10211
Merge branch 'master' into feature-slidingnavigation-mab-master

Conflicts:
	Kernel/Output/HTML/Standard/AgentNavigationBar.dtl
Fixed: Navigation broken if many modules installed (bug#6802).
Merge branch 'feature-slidingnavigation-mab-master'
Merge remote-tracking branch 'upstream/master'