When git merges are in use it appears that --shallow-since=DATE stops at
the first merge commit that is older than DATE. This could create a too
shallow clone that lacks the desired commit. Disable this optimization.
Observed with git 2.19.1.

Fixes #359

Test migration during handshake and by spoofed packets

Add API for multiple spin bit variants

Simpler interaction between PMTU disc and wake time

Key rotation

Add capability to select network interface on client

Asymmetric packet flows broken by dest_if code.

Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>

Signed-off-by: Debabrata Banerjee <dbanerje@akamai.com>

Fixes for draft-15 interop