Need stress tests for file locking / concurrency

[dotsdl]

Despite the advantages of structuring Containers with their stored data at the filesystem level instead of shoving them into a single database, the major disadvantage is that we have to be careful that file locks are working to ensure against concurrency corruption. We need stress tests of the file locking mechanisms for:

• ContainerFile and its child classes
• DataFile variants

We also need to test that changes in filesystem elements that occur through Container properties (e.g. #19) are also handled gracefully, though this will almost certainly require the underlying ContainerFile object to use the Foxhound to fetch its new path.

[dotsdl]

Moved to datreant: datreant/datreant#6