uses infopark menu bar

+ positions and styles edit button to match the close button within the menu bar
+ removes workspace toggle, which is now part of the menu bar
moves widget templates to "views" folder
changes system title attribute to custom headline attribute
removes headline from search page
switches system body attribute to custom content attribute

+ fixes some translation key namings in widgets
+ fixes and extends specs to check for the new custom attribute
supports cms_tag_list helper
bugfix: image widget did not use the new cms_image_tag style
Merge branch 'feature/extend-inplace' into develop

* feature/extend-inplace:
  bugfix: image widget did not use the new cms_image_tag style
  supports cms_tag_list helper
  switches system body attribute to custom content attribute
  removes headline from search page
  changes system title attribute to custom headline attribute
  moves widget templates to "views" folder
  uses infopark menu bar