v1.5.0

This release brings some new features, improvements and bugfixes:

• Improve handling of exceptions from callback handlers
• Add support for async registration of matches
• Correctly add libsystemd dependency to pkgconfi
• Fix request name signal handling issue
• Add INSTALL_TESTS CMake option
• Minor UnixFd cleanups
• Additional little fixes and updates in code, build system, CI, and documentation