Move log warnings about ignored ivy file content down to debug level. 

- Ideally, these should only be logged once when the module is actually resolved from a remote repository. 
- Once we don't use ivy.xml for internal meta-data persistence, we should be able to move these messages up to WARN, I think.
- Also, used the correct string substitution characters for log messages
Improved usefulness of log message: it was reporting default toString() representation