t3301: abstract away SHA-1-specific constants

t3301: abstract away SHA-1-specific constants

Adjust the test so that it computes variables for object IDs instead of
using hard-coded hashes.  Move some invocations of test_commit around so
that we can compute the object IDs for these commits.

Compute several object IDs in the tests instead of using hard-coded
values so that the test works with any hash algorithm.  Since the actual
values are sorted by the object ID of the object being annotated, sort
the expected values accordingly as well.

Signed-off-by: brian m. carlson <sandals@crustytoothpaste.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>