RoxenPatch: Run patch in binary mode on WIN32.

The patch binary on WIN32 defaults to breaking the linefeeds in patches
for files that use CRLF as EOL. Fix it by always opening the files in
binary mode.

Fixes [bug 7244].
Merge branch 'patches/bug7244' into grubba/patchsystem

* patches/bug7244:
  RoxenPatch: Run patch in binary mode on WIN32.