Bump go.mod and README. Switch to upstream net/netip. Use strings.Cut. Signed-off-by: Josh Bleecher Snyder <josh@tailscale.com>
There are more places where we'll need to add it later, when Go 1.18 comes out with support for it in the "net" package. Also, allowedips still uses slices internally, which might be suboptimal. Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
