bug fix for NetCDF endian problem (trac ticket #1720)

This pull request is an attempt to fix the problem found in trac ticket #1720
 ( http://projects.scipy.org/scipy/ticket/1720 )

Changeset 76a983ec625 removed the explicit conversion of all outgoing
datatypes into big-endian format (e.g. see page 10 of
http://earthdata.nasa.gov/sites/default/files/esdswg/spg/rfc/esds-rfc-011/ESDS-RFC-011v1.00.pdf)

This changeset (eelsirhc/scipy@d2b5014c2a) converts the type to big-endian during the array creation in createVariable by calling the dtype.newbyteorder
function with the argument "B" for Big endian.