Draft: WIP: Retain original test definition order

The current version of pyfeeds creates the final list of tests from a sorted set of input directories. This WIP changes the creation to use a key-only dict to preserve the original order if multiple test directories were specified on the command line. This might be helpful when following how the tests are progressing ( maybe the final version would make this a command line option ). Do not merge for now - this is just an idea for discussion