Patch Set 1: Looks good to me, but someone else must approve; IP review completed

This series of 3 commits has been sitting on my desktop since September. I posted it to the git ML before we moved our repository to eclipse.org, but no discussion happened, and it appears to have been dropped.

Since it fixes issues in DirCache relating to applications being able to create bogus data structures, I'm reviving it and trying to get it in before 0.7.0.