[PATCH 0 of 2] Split "mq: fix patch names/paths mismatch under win32"

[Patrick Mezard]

First patch ensure all mercurial generated patch names are unixish. It makes tests to pass under win32.

The second one enforce the unix name policy to all patch names including the ones supplied in series. It will break win32 patches repository already using subdirectories. To fix it, just replace backslashes with slashes.