UI/API changes

• NEW: Sponsor card on homepage
• FIX: Tags in measurement details now link to measurement search
• FIX: Credit history linking to new measurement details page
• FIX: Apply for probe button should link to new www info
• TWEAK: Formatting of tables in coverage
• TWEAK: Text of system status popup
• UPDATE: Menu/header component with fixes for click recognition and external login redirection