* Fixed navicon left align, not it's centered properly
* Added new icon font for "back to material view" 
* Adjusted workspace.js script for right side additional navigation in
material's reading view
* Added button so user can go back to material view from reading view
#442
* Changed every workspace navigation widget's class to be more precise
* Added new icon fonts to assest as well
* Added new widget workspace-materials-reading-goback and created
widgetspace in materialäs rading view for the future use
Merge branch 'FTR-50-WORKSPACE-VIEWS' of https://github.com/otavanopisto/muikku.git into FTR-50-WORKSPACE-VIEWS