ISLANDORA-1129 Don't use default pattern when specific is available

If any of an object's content models have been enabled for pathauto,
then only create those applicable aliases.

Formerly, all objects were going through pathauto using cmodel
fedora-model:FedoraObject3.0, which was applying the default pattern
if set.
Updated README to clarify edge case
Removed debugging code
Merge pull request #7 from rosiel/7.x-ISLANDORA-1129

7.x islandora 1129