Define what is a conclusive "To-From" mapping in the develop_to_deploy pipeline

[pombredanne]

When we have a single path mapped this is a weak mapping. We will need to further classify each To-From relationship quality. A relationship could be further analyzed based:

• on the parsed Java package + class(es) and parsed .class package + class(es)
• on matching symbols and strings on both sides

See also #675

[pombredanne]

This is closely related to the new #905 house keeping step in d2d