This is a fork of Paul Hsieh's Better String Library
<https://bstring.sourceforge.net/>. The following features (or
mis-features, depending on your point of view) are included:

1. Autotools build system
2. Updated test suite based on Check
3. Add Valgrind to the workflow
4. Add continuous integration via GitHub Actions
5. Remove C++ code
6. Other various improvements

Currently this fork should be binary-compatible with the original
code. The only source incompatibility is the removal of the
`const_bstring` type.