pack-objects: clarification & option checks for --max-pack-size
pack-objects: clarification & option checks for --max-pack-size

Explain the special code for detecting a corner-case error,
and complain about --stdout & --max-pack-size being used together.

Signed-off-by: Dana L. How <518cfd113377207d025b88757a8df40a2fb38c08@gmail.com>
Signed-off-by: Junio C Hamano <dc50d1021234060e53ec42a77d526afa2fe07479@cox.net>

destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git,destenson/git