dir/server/serverlog: add a dump program that can print the contents of server logs
dir/server/serverlog: add a dump program that can print the contents of server logs

Change-Id: Ieb00a0223a99c334ef940bd169b8d1c0a05f38d5
Reviewed-on: https://upspin-review.googlesource.com/14361
Reviewed-by: David Presotto <d244755566b06d4c956c05eb7fe29c9fb345f41e@gmail.com>

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