Windows: Wrong file location path comments in .po files generated by makemessages

[Ramiro Morales]

The comments associated with literals found on files of the 'django' domain that aren't Python source code end like this (from the test suite):

# .\template\test.html.py:55
msgid "The translatable literal here"

it should be:

# template\test.html:55
msgid "The translatable literal here"

to be on par with the file generated on Unix, or even possibly:

# .\template\test.html:55
msgid "The translatable literal here"

But the .py prefix shouldn't be leaked.