This test verifies that TAO::Storable_FlatFileStream along
with TAO::Storable_File_Guard can be used to save/restore
the state of an object (an instance of Savable) to the
file system. To verifing Storable_File_Guard's file locking,
two processes that read/write from the persistent store run
in parallel.

Note that this test does not explicitly validate the code in
Storable_File_Guard that deals with the persistent store
being obsolete.