doc: make sure we use our own code for generating man pages
docutils would in some situations pick up its own manpage.py instead of
doc/manpage.py. Renaming to hgmanpage.py makes it less ambiguous.
#!/bin/sh
hg init
echo a > a
hg ci -Am t
hg mv a b
hg ci -Am t1
hg debugrename b
hg mv b a
hg ci -Am t2
hg debugrename a
echo % test with --rev
hg debugrename --rev 1 b