transitive copy/rename
Add support for transitive copy or rename operations, e.g.
hg rename a b
... (possibly edit b)
hg rename b c
hg commit ...
by actually renaming "b" as "c" while recording a copy of
"a" to "c" and a removal of "a".
abort: Failed to parse .../t/.hg/hgrc
File contains no section headers.
file: .../t/.hg/hgrc, line: 1
'invalid\n'