In versions <= 2.15 the old regexp caused any file or directory beginning with . to be ignored during a backup. This has caused behavioral differences in 2.16 because the new C code correctly excludes ./.. directories.
This Perl code is only used for testing now, but it should still match the output of the C functions.
The tests and documentation have been using the core storage layer but soon that will depend entirely on the C library, creating a bootstrap problem (i.e. the storage layer will be needed to build the C library).
Create a simplified Posix storage layer to be used by documentation and the parts of the test code that build and execute the actual tests. The actual tests will still use the core storage driver so they can interact with any type of storage.
