Redesign 'Add Kart' template

closes #20, closes #32
Add mechanic image to Add Kart template
Remove Tab-key override
Update test_views
Fix cancel button

closes #48
Update menu URLs
Add standalone 'Add Kart' page

* add-kart-#32:
  Update menu URLs
  Fix cancel button
  Update test_views
  Remove Tab-key override
  Add mechanic image to Add Kart template
  Redesign 'Add Kart' template