Ok thanks for the detailed info, Martin

I guess we could refactor it to an xml reader/writer if we need to do
more things in the future with these files.

I'll close this issue, as the mentioned problem is now fixed by using a
text mode. The test in test_msvc9compiler will make sure the XML file 
gets cleaned up by the regexp.

- done in r76993, r76995
- backported in r76996 and r76998 so the trunk behaves the same way.
- 2.6 stays unchanged, and keep using a binary mode.

Thanks all !