Merge pull request dateutil#831 from pganssle/release_2.7.5

Release 2.7.5

Merge pull request dateutil#828 from pganssle/release_2.7.4

Update NEWS with changes for 2.7.4

Version 2.7.3

Release 2.7.2

Merge pull request dateutil#649 from pganssle/release_2.7.1

Release 2.7.1

Release 2.7.0

Merge pull request dateutil#413 from pganssle/prepare-2.6.1

Prepare 2.6.1

Release 2.6.0.

Merge pull request dateutil#255 from pganssle/prepare-2.5.3-release

Prepare 2.5.3 release.

Merge pull request dateutil#231 from pganssle/prepare-2.5.2

Prepare 2.5.2 release.