evert/SabreDAV — pull request #311 by DeepDiver1975 (2013-01-19 14:55:20+00:00)
Title: xml-encoding values in sabredav error responses.

Fixes Issue #237 in 1.6

@evert:
This PR is actually just
````
git checkout 1.6
git cherry-pick 1d5e42cabbf193896f905a5c2e264c2d83d8f9e4
````

Up to you: merge the pull request or execute the commands your self! ;-)