revlog: reorder index accessors to match data structure order
Index entries are ordered tuples. We have accessors in the revlog
class to map tuple offsets to names. To help reinforce the order,
reorder the methods so they match the order of elements in the
tuple. While I'm here, also sneak in some minimal documentation.
#require docutils gettext
$ $TESTDIR/check-gendoc pt_BR
checking for parse errors