Maintenance release for v0.2.2. Tests ported to test-framework.
All API change are backwards compatible.
Bug-fix release for v0.2.1. All API changes are backwards
compatible: the ToString type-class is exported. Fixes the
interpolation of Chars (thank you nh2).
Bug-fix release for v0.2.0. It does not change the API in any way,
but adds a few more tests and some more documentation.