rust-cpython: consistency in use of hg-core constructs
While not everybody likes the `CoreLazy` and `CoreIterator`
aliases, it's better not to mix them with direct references.
Note: it's quite possible in the future that these would stop
being exposed at the top of the `hg` crate
Differential Revision: https://phab.mercurial-scm.org/D5547
#require docutils gettext
$ $TESTDIR/check-gendoc de
checking for parse errors
Die Dateien werden dem Projektarchiv beim n\xc3\xa4chsten \xc3\x9cbernehmen (commit) hinzugef\xc3\xbcgt. Um dies vorher r\xc3\xbcckg\xc3\xa4ngig zu machen, siehe:hg:`forget`. (esc)
warning: please have a space before :hg: