RFR: Convert path separators in patch file to unix explicitly

[JornVernee via github.com]

The pull request has been updated with additional changes.

----------------

Added commits:
 - 169b6867:	Convert path separator in Patch::write to unix as well.

Pull request:
http://git.openjdk.java.net/skara/pull/35

Webrevs:
 - full: https://openjdk.github.io/cr/skara/35/webrev.01
 - inc: https://openjdk.github.io/cr/skara/35/webrev.00-01

Updated full patch:
http://git.openjdk.java.net/skara/pull/35.diff

Fetch command:
git fetch https://github.com/openjdk/skara.git pull/35/head:pull/35