pass optional paths for trained models to the reader allowing for using ...

...multiple models in the same import. Using global paths is still allowed

Paths are now contained in metadata and are stripped when they are saved. Readers and Taggers are now can use paths in md members. The only thing that still looks sketchy, is the Affix class, as it is a singleton container for affixes in the data folder (which may be customized). This may be as well just a member of the Reader class and contained with it.

In the /bin directory:
Only nlpnet-train and nlpnet-tag were checked for correctness. Other scripts may need a review too. Since reader now gets metadata to the constructor, create_converter doesn't require md as a parameter.