Finish the flow-map insertion point cleanup across the spec.

Section 2 semantics 6 in 06 still defined recording as happening with the SYN-ACK, which contradicted 00, 07 and 08 after the A1 wording; fix it, the 07 C-NR-301 cell (which also said 'after syncache_insert'), the leftover 06 DR2 wording, the drifted line reference and the real hook name. 09 keeps its v1.8 record and points at the current wording.

Author: fengbojiang