Updated DataView_Tutorial to be Python <=2.6 compatible
Updated DataView_Tutorial to be Python <=2.6 compatible

mjabri/holoviews,basnijholt/holoviews,ioam/holoviews,basnijholt/holoviews,ioam/holoviews,mjabri/holoviews,vascotenner/holoviews,vascotenner/holoviews,mjabri/holoviews,ioam/holoviews,basnijholt/holoviews,vascotenner/holoviews