It depends heavily on the expression at the call site an whether it can
figure out whether we're using a slice or not, so provid an incantation
that does this.
An Object should be about representing a libgit2 object rather than
showing which methods it should support.
Change any return of Object to *Object and provide methods to convert
between this and the particular type.
Provide a manual way of freeing objects, but set finalizers for them
in case the user does not want to worry about memory management, which
would be useful for commits or trees, which sare typically small.
When the objects are freed manually, the finalizer is unset to avoid
double-freeing, mimicking what the go runtime does.
Carlos Martín Nieto
Michael Gehring
Patrick Steinhardt
Jesse Ezell
Vicent Marti