* Update helpcontent2 from branch 'master'
  - Show module & lang navigation on mobile
    
    Module & languages menus were not shown on screen widths < 960.
    
    Changed module & languages menu background to span the whole
    width, when on mobile.
    
    An arrow function was used in help2.js, which means it was broken
    on IE.
    
    Moved all src .js files to head and used defer for all.
    
    Moved inline Piwik & system info JS into help2.js and added a
    test for onlineness targeting the first meta element in the body.
    
    Change-Id: Ic1a928b53ce9029f9f655117977cd511b7e3246d
    Reviewed-on: https://gerrit.libreoffice.org/69005
    Tested-by: Jenkins
Reviewed-by: Olivier Hallot <olivier.hallot@libreoffice.org>