new CubeList method to extract over common coord values
Changed to generator comprehension
Default NetCDF dimensionless unit.
Simplify circularity test in nc load rules.
Define circularity from bounds, if any.
Added tests for old+new circular logic.
bump version to v1.8.0-dev after v1.7.x branch
Merge pull request #1205 from esc24/bumpversionto1.8

bump version to v1.8.0-dev after v1.7.x branch
Added slice_over cube method
grib save statistic
Merge pull request #1228 from marqh/gribsavestat

grib save statistic
Merge remote branch 'upstream/v1.7.x' into refresh

Conflicts:
	lib/iris/__init__.py
	setup.py
Allow datetime-like values for LinearInterpolator.
Review actions
Further review actions: tests improvements
Merge pull request #1229 from dkillick/slice_over

Added cube method slices_over
Merge pull request #1238 from SciTools/v1.7.x

Merging v1.7.x on to master
Ensure dates-as-nums are floats.
Added skip_data decorator to two tests missing it
Merge pull request #1242 from dkillick/tests_missing_skipdata

Added skip_data decorator to two tests using test data without it