[MNG-6071] Normalize relative paths for working directory

[slachiewicz]

https://builds.apache.org/job/maven-box/job/maven/job/MNG-6520

[eolivelli]

This is very like the surefire issue.
But we need to write tests

[Tibor17]

@slachiewicz
It would be worth to commit this change in concrete version. Why we did not negotiate the version for such simple fix on mailing list?

[slachiewicz]

i need to write unit tests - i run multiple runa by hand while investigating root couse, but now I have less time to add few more tests to code. I look into this later. I already send few other pathes to mailing list - waiting for review and more are ready.

[slachiewicz]

@eolivelli @Tibor17 I'm unable to create a unit test for this change. Inside maven everything works fine, only with surefire it makes the problem because getClass.getResource inside java rejects "." inside classpath entry.
It this change would not make any side effects - it would be good to see clean paths to poms/workspace

[eolivelli]

Let's ship it in the current form as far as all tests pass on our Jenkins matrix