bkw777/mainline v1.0.3

on GitHub

Change setting kernel_version_threshold (show kernels of major version N and newer),
to show_prev_majors (show kernels of major version current highest minus N).
0 or 1 are sensible values, meaning 0 = always show only the current highest major version, or 1 = always show the current highest and one previous major versions.
The point is the user does not have to manually update the setting over time.