Prepare change log for v0.7.1. (#263)

Prepare change log for v0.7.0. (#260)

Additionally:

- Extend change log by PR 259.
- Add missing links for version 0.6.0 release.

Merge pull request #249 from gambol99/release-0.6.0

Prepare change log for v0.6.0.

Merge pull request #240 from gambol99/release-0.5.1

Prepare change log for v0.5.1.

Merge pull request #236 from gambol99/release-0.5.0

Prepare change log for v0.5.0.

Merge pull request #228 from gambol99/release-0.4.0

Prepare change log for v0.4.0.

Prepare change log for v0.3.0.

Merge pull request #203 from gambol99/release-v0.2.0

Prepare change log for v0.2.0.

Update change log for 0.1.1 release.

Add Mike Solomon to list of authors.