datastore test suite. Add a new test corpus file, located so
as to test the backward compatibility functionality of
FileSystemSource. Add a test to the suite which ensures that
this new file is found.
Factored out the _is_marking() function from the memory datastore
module to utils so it can be reused, and changed both filesystem
and memory datastore modules to import and use it.
Factored out the _is_marking() function from the memory datastore
module to utils so it can be reused, and changed both filesystem
and memory datastore modules to import and use it.
Michael Chisholm