Add Phase 17 (p4 snap), fix Phase 6/9/12 bugs, add session log (v3.0.0)
New features:
- Phase 17: Snap lazy copies; -snap flag resolves cross-depot archive
references, eliminating depot name leakage at the archive layer.
- Without -snap, Phase 17 proposes the p4 snap commands for review.
New Operator Tips in -man for snap/journal patch ordering.
Bug fixes:
- p4 fix -d: was passing invalid -j flag; job name is positional.
- p4 server -d: was passing invalid -f flag.
- Shelved CL failures: now correctly reported via errmsg().