Remove obsolete IrisTest._assert_cml().
Merge pull request #1006 from rhattersley/remove-obsolete-test-method

Remove obsolete IrisTest._assert_cml().
Show full reference file path on test failure.
Sphinx data documenter for instances.
Merge pull request #1009 from bjlittle/sphinx_opaque_agg

Sphinx data documenter for instances.
Merge pull request #1007 from rhattersley/show-path-in-test-failure

Show full reference file path on test failure.
Improved error message on unit conversion failure
Merge pull request #1002 from bblay/conc-mask

concat mask
Pointed to direct link for Python NetCDF location.
Merge pull request #1019 from pelson/travis_fix

Pointed to direct link for Python NetCDF location.
Merge pull request #1011 from dkillick/conv_unit_fail_msg

Improved error message on unit conversion failure
agg doc