Mention 4.2.2-post1 in changelog.

Fixed formatting as well.

Bump version: 4.2.1 → 4.2.2

Bump version: 4.2.0 → 4.2.1

Bump version: 4.1.0 → 4.2.0

Bump version: 4.0.2 → 4.1.0

Bump version: 4.0.1 → 4.0.2

Bump version: 4.0.0 → 4.0.1

Sets release date for 4.0

Bumps version to 4.0.0rc6

Bumps version to 4.0.0rc5