t5300: add test for "unpack-objects --strict"
t5300: add test for "unpack-objects --strict"

This adds test for unpacking deltified objects with --strict option.

 - unpacking full trees with --strict should pass;

 - unpacking only trees with --strict should be rejected due to
   missing blobs;

 - unpacking only trees with --strict into an existing
   repository with necessary blobs should succeed.

Signed-off-by: Junio C Hamano <a6723cc3f76163bf7adb636a73ac3b0ceb3e6b9b@pobox.com>

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