Validation to produce XML output

Created by: Anonymous

Original issue 264 created by @ysavourel on 2012-08-07T00:23:06.000Z:

The current outputs of QualityCheckSession.generateReport are html
and tab-separated values.
Tab separated values is a problem if the segments have line breaks,
and the html is hard to parse.
So it might be nice if we would also generates an XML report.

See thread: https://groups.google.com/forum/?fromgroups\#!topic/okapi-devel/hDqA25qFYsM