Convert outgoing netCDF arrays to big-endian

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 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.
TST: io: add regression test for netcdf fix
Merge pull request #471 from oth/upstream/pr/471

BUG: io: Convert outgoing netCDF arrays to big-endian
TST: io: minor clean up in netcdf tests
Add a list of generated files to .gitignore
DOC: stats: fix some references to other functions in docstrings
DOC: document that first input to fftconvolve has to be larger than second input
MAINT: optimize: remove some unused variables from show_options() in optimize.py
BUG: fix invalid py3k syntax (u'') in savemat tests.

Introduced by https://github.com/scipy/scipy/pull/452

Ticket 1858 may be related, reports more failures caused by the same PR.
Use explicit filenames rather than globs
Check directly for elements in dictionaries, not their .keys()
Iterate directly over dictionaries, not their .keys()
fixed bug in clpmn violating array bounds
test for bug in clpmn
FIX: replace spurious 1.0E+12 by finfo(float).max in slsqp

As discussed in PR#449 <https://github.com/scipy/scipy/pull/449>
add regression test for issue 1876
Merge pull request #482 from gertingold/clpmn

BUG: special: fixed bug in clpmn violating array bounds
MAINT: signal: clean up some C code to eliminate a few compiler warnings
change assert_ to assert_equal
Merge pull request #484 from jakevdp/csgraph1876_test

TST: sparse.csgraph: add regression test for issue 1876