Bump the version to 0.2.4 and update the NEWS file.

Bump the version to 0.2.3 and update the NEWS file.

Bumps the version to 0.2.2 and updates the NEWS file.

Bumps the version to 0.2.1 and updates the NEWS file.

This is in preparation for a CRAN release.

Bumps to version 0.2.0 and updates the NEWS file.

Bumps the version to 0.1.3 and updates the NEWS file.

Bumps the version to 0.1.2 and updates the NEWS file.

Bumps the version to 0.1.1 and updates the NEWS file.

Marks version 0.1.0 and adds a NEWS file.