Tests that rely on the exact hardcoded values of object names have
been updated in preparation for hash function migration.
* bc/hash-independent-tests:
t2107: abstract away SHA-1-specific constants
t2101: abstract away SHA-1-specific constants
t2101: modernize test style
t2020: abstract away SHA-1 specific constants
t1507: abstract away SHA-1-specific constants
t1411: abstract away SHA-1-specific constants
t1405: sort reflog entries in a hash-independent way
t1300: abstract away SHA-1-specific constants
t1304: abstract away SHA-1-specific constants
t1011: abstract away SHA-1-specific constants