Bugs fixed:
- tdiff could fail on Linux with O_NOATIME support when comparing files or reading directories not owned by the invoking user, when not running as root.
Other changes:
- Specify better tdiff's behavior with regards to O_NOATIME.
- Spec file now BuildRequires fakeroot.
- Enhanced test suite / regressions.
- Don't abort() on unexpected state, exit cleanly.
- Fix nanosecond resolution detection in regressions.