Bug fix and patch version bump.

Update rtcgps.cc example.

- Remove the featherlib scheduling support.

Bump patch version to 0.3.4.

Bump patch version to v0.3.3.

Bump patch version to 0.3.2.

Bump patch version to 0.3.1.

Bump minor version to 0.3.0.

Bump patch version to 0.2.5.

Bump patch version to 0.2.4.

Update CHANGELOG and README.