Added import support for mayavi 4.0 in vis. Still need to update examples
Added import support for mayavi 4.0 in vis. Still need to update examples

mtb-za/fatiando,mtb-za/fatiando,eusoubrasileiro/fatiando_seismic,eusoubrasileiro/fatiando,eusoubrasileiro/fatiando,drandykass/fatiando,fatiando/fatiando,victortxa/fatiando,eusoubrasileiro/fatiando_seismic,rafaelmds/fatiando,fatiando/fatiando,rafaelmds/fatiando,santis19/fatiando,cmeessen/fatiando,santis19/fatiando,drandykass/fatiando,eusoubrasileiro/fatiando,cmeessen/fatiando,victortxa/fatiando