* Swap out Biggus concatenate for Dask concatenate

* Re-enable passing concatenate tests

* fixed typo lazy_array to lazy_data; give fill_value attribute to all lazy data

)

* Changed most occurrences of biggus.Array instance checks to either dask.array.Array instance checks or lazy data checks

* updated headers

* header dates corrected whitespace removed

…ols#2388)

Core refactor for dask usage

* daskifying stats and maths

…ools#2401)

* Refactor AuxCoordFactory unit tests to remove biggus references

* passing tests unskipped

* esmpy regrid skips removed

* Existing lazy stats working, mean / std / var, with mdtol-action wrapper.
* Enable and test lazy collapse over multiple dimensions.

* Fix FieldCollation.data; Replace uses of PPField._data outside the class with core_data or data. Fix unittests

* daskify_intersection

* removed skippers for passing tests

* Reinstate func and uses in Iris code

* Tests use new func, tests for new func

* lazy data func handles masked arrays

* Review actions

* Remove missed spurious chunk sizes

* Review action: reference a function as a function

Use multidimension dask stacks in merge and fast um loading.

Tighten purpose of `array_masked_to_nans`

* Testing ideas for cube data/dtype/fill_value interaction (not passing -- need new API).

* Add checks for realisation; fix dtype tests; use 'lazy' keyword instead of 'real'.

* With test failures to investigate.

* Fixed tests for new code from SciTools#2433.

* Fix tests

* Pep8 fix.

* Fixed data_dtype_fillvalue test fails (other things now failing).

* Fix bug in clearing _dask_array when assigning real data.

* Keep fill value of cube when resetting the cube's data

* Fix concatenate tests.

* Keep fill values during stats operations; cast cml fill values to float64.

* Keep fill values during regrid test.

* Fix basic maths tests.

* Tidy cube.__init__ for dtype setting.

* Review actions.

* Rename concatenate unit tests.

* Review actions.

* pep8

* Consistent checking for ma

* License headers

* Fix missed instances

* NetCDF save with dask support

* Refactor and use array_nans_to_masked

* Add array_nans_to_masked test coverage.

* Refactor.

* Working tests.

* Update comment detail for convert usage.

* Use array.dtype in convert_nans_array

* Review actions.

* Review actions.

…ciTools#2447)

Replace dask 'compute()' usage with a common realisation call.

)

Remove some biggus skippers.

* Fix for dtype.kind

Only use truediv

Remove biggus imports

Add data manager with tests.

* pp save return field's data as masked array; fix test to check fill value of cube not data, and cube's dtype

* Fix bmdis of fields that were saved from global.pp test data

* Fix import order.

* Review actions.

Dask opts controlled by simple function

Fix translation generator tool to use internal grib module.

…ition 1 and 2

* Use DataManager for CellMeasures data.

* Review changes: clearer comments.

* Add lazy data tests

* Add masked saving test

* Review actions: license dates, test updates

* Prevent sliced measures data being a view on the parent.

* Pep8 fix.

* Review changes.

* Initial integration

* Renames + data_manager tests.

* Add missing cube.copy return + pep8

* Fixed concatenate + added cube.replace with tests

* Fix test_Cube.py

* Fix test_fast_load.py dtype setter.

* Fix test_cdm.py metadata.

* Fix merge + fill-value failures

* licence years + numpy maskedconstant dtype fix

* Fix merge as_concrete_data result_dtype

* Use Cube.replace for data + fill-value setting.

* Remove _lazy_data imports from cube.

* Minor refactor of _deepcopy.

* Minor ProtoCube._get_cube tidy.

* Update test case comment.

* Update iris.cube.Cube doc-string.

* Align data & cube fill-value + supporting tests.

* Fix replace corner case.

* Added cube.__getitem__ test.

* Fix merge + merge fill-value promote.

* Fix concatenate + concatenate fill-value promote.

* Add dask issue reference + use np.promote_types.

* Added extra review action tests.

…#2517)

* Prevent sliced coords sharing data with their parent coord.

* Fix (and test) null slicing [:, :, ...] specifically.

* Simplify coord getitem code.

* Review changes.

Remove `LazyArray` class

* DataManager.core_data()

* Cube.core_data()

* Fileformats rules core_data()

* Fix concatenate fill value.

* Fix merge fill value.

* Added merge invariant tests.

* Added concatenate invariant tests.

* Review actions.

* Simplify merge/concatenate match condition.

* expected_fill_value

* Some changes on the way to getting lazy AuxCoords in an actual load.

* Unify getitem code between Cube, Coord and CellMeasures.

* Review changes: Simplify + document '_slice_data_with_keys' function.

* Further review changes; functional tests for iris.util._slice_data_with_keys.

* Added purely results-based tests.

Integrate DataManager with Coord classes

* Propogate masked fill-value to dm.

* Fix existing CML.

* __init__ fill-value 'none' and None

* Fix broken DataManager tests.

* Add propogate test coverage + minor refactor

* Fix typo

* Review actions.

…ools#2547)

* Enhanced Coord tests including new dask+lazy functionality.

* Review changes: remove skips, legacy support and debug code.

* Factor out common test code.

* Test init on all combinations; test with bounds dtype different from points.

* Review changes to tests.unit.coords module.

* Pep8 fix.

* Review changes.

…ciTools#2543)

* Make NetCDFDataProxy dtype equal nan_array dtype

* Handle PPDataProxy. Require correct dtype to be passed to BetCDFProxy initialiser

* Update cml files

* Always return array of specified dtype, even if the type would be promotable

* Add data_dtype property to field classes

* Add test for partial mask in pp file

* Update test data sha

* Use data_dtype to construct grib proxy

* Minor tweaks

* data_dtype -> realised_dtype

* Refactor Coord inheritance.

* Review changes.

* Review change -- reword comments for clarity.

* Fix Python3-specific problem.