Added a method to add a project as a depedency

to FileUtil
Deleting the file after the test
Moved the zip-file-listing-method to FileUtil
Moved the reading of the ignoredProjects

This avoids a NullPointerException in some cases
Made two methods synchronized

As a hope of curing a Heisenbug...
Added a Thread.sleep()

So the job has a chance to finish. Yes, I know that this should
be done with a ProgressMonitor, but getting one that deep right
now is a bit too much work.

This is the lazy-man approach to completion.
Added tear-down method that deletes all the zip files
Using the field
Added test for dependent projects

A bit useless, but it's there, why not. Oh, and it does not catch the
bug...
Merge pull request #110 from caiusb/snapshot-bug

Snapshot bug