When we turned strict object creation validation on by default, we
forgot to inform the refs::create tests of this. They, in fact,
believed that strict object creation was off by default. As a result,
their cleanup function went and turned strict object creation off for
the remaining tests.
The signature for the reflog is not something which changes
dynamically. Almost all uses will be NULL, since we want for the
repository's default identity to be used, making it noise.
In order to allow for changing the identity, we instead provide
git_repository_set_ident() and git_repository_ident() which allow a user
to override the choice of signature.
Any well-behaved program should write a descriptive message to the
reflog whenever it updates a reference. Let's make this more prominent
by removing the version without the reflog parameters.
