py3: add PY23() macro to switch string literal depending on python version
I have no better idea to work around the bytes-unicode divergence of
Py_BuildValue(). Maybe we can write a code transformer for C extensions? :)
$ hg init
$ touch unknown
$ touch a
$ hg add a
$ hg ci -m "1"
$ touch b
$ hg add b
$ hg ci -m "2"
Should show unknown
$ hg status
? unknown
$ hg revert -r 0 --all
removing b
Should show unknown and b removed
$ hg status
R b
? unknown
Should show a and unknown
$ ls
a
unknown