upgrade: document DELTAREUSEFULLADD in revlog.clone...
upgrade: document DELTAREUSEFULLADD in revlog.clone
The documentation of the `debugupgraderepo` command was updated when
`re-delta-fulladd` was introduced. However, the docstring of the `revlog.clone`
method was not.
Differential Revision:
https://phab.mercurial-scm.org/D6900