Adds option to allow prefixing the class name in an xunit report

[joscha]

In a matrixed build environment (for example running tests with tox) and producing multiple xunit reports, a report crawler (for example from Bamboo) can not distinguish between results in different environments, because the class name is always the same.
In order to allow distinguishing between failures in different environments, this PR adds an option --xunit-prefix-with-testsuite-name to the nose-xunit plugin.

A test result looking like this with --with-xunit:

<testcase classname="tests.x.y" name="somename" time="0.000">

becomes:

<testcase classname="nosetests.tests.x.y" name="somename" time="0.000">

with --with-xunit --xunit-prefix-with-testsuite-name
or:

<testcase classname="foo.tests.x.y" name="somename" time="0.000">

with --with-xunit --xunit-testsuite-name=foo --xunit-prefix-with-testsuite-name.

Side note: It works in a similar manner as the useBrowserName option in the karma-junit-reporter.

Fixes #402

[dirk-thomas]

This patch implement a very valuable and long requested feature (#402).

I have the same problem that Jenkins only shows the classname but with multiple packages being tested it is unclear to which each of them belongs. The job already uses --xunit-testsuite-name=... but Jenkins does not utilize the testsuite name attribute. This new option would solve that.

[jszakmeister]

This all looks good with one exception: I expected to see a test that uses xunit-testsuite-name to change the prefix. Do you mind adding such a test?

[joscha]

I thought adding the default would be enough. Additional test is in ab198aa

[joscha]

@jszakmeister I added the additional test in ab198aa and rebased to master

[jszakmeister]

Great! Thanks!

[joscha]

Thanks for integrating!

[dirk-thomas]

Great! Can I assume that this will be released in 1.3.8 at some point in the future?

[jszakmeister]

Hopefully. I'm not making any promises--I'm stepping down as maintainer soon.