Don't crash on empty src attrs. Fixes [Bug 7243].
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.
Merge branch 'grubba/patchsystem' into devel

* grubba/patchsystem:
  RoxenPatch: Run patch in binary mode on WIN32.