Concatenate with scalar coordinate.
Review actions.
Preserve the datatype of time arrays converted with Unit.
Merge pull request #1385 from pelson/unit_convert_dtype

Preserve the datatype of time arrays converted with Unit.
Updated whatsnew for v1.7.2 release4
Merge pull request #1388 from dkillick/whatsnew-v1.7.2

DOC: Updated whatsnew for v1.7.2 release
Bump version to v1.7.2-rc.1
Merge pull request #1389 from dkillick/v172-rc1

Bump version to v1.7.2-rc.1
Bump version to v1.7.3-DEV
Merge pull request #1390 from dkillick/v173-dev

Bump version to v1.7.3-DEV
Changes for releasing v1.7.2
Merge pull request #1406 from dkillick/release_v1.7.2

Release v1.7.2
Bump version to v1.7.3-dev
Merge pull request #1407 from dkillick/update_v1.7.3-dev

Bump version to v1.7.3-DEV
Prevent arbitrary SplittableInt in lbtim.
Simplify lbproc == 128 handling.
Check that cube.copy() makes a fresh mask.
Tidy test code.
Merge pull request #1417 from rhattersley/lbtim

Prevent arbitrary SplittableInt in lbtim.
Merge pull request #1418 from rhattersley/bogus-rule

Simplify lbproc == 128 handling.