Main navigation menu [JIRA CVRE-206]

Main navigation menu: make the search box broader and display “search the CENDARI resources”; the “Browse”-Tab is dysfunctional (one receives “Ooops”); in the top row there should be provided a “Help”-button with a link to the help sections of the portal https://docs.cendari.dariah.eu/user.html or better, once implemented, to the new CENDARI homepage and the help sections over there; take out the unimportant tabs (Issue Report, Survey)

reported by AndreiZamoiski on 2015-12-16T13:53:11.385+0100