`multiproduct.env.ProductEnvironment`: Refactoring - Access path value in SplitResult object by attribute (available since Python 2.5) rather than index, to improve code clarity.

Added tests for `href` attribute. Refs #595.

git-svn-id: https://svn.apache.org/repos/asf/bloodhound/trunk@1511640 13f79535-47bb-0310-9956-ffa450edef68