Added new callback onEntityInfoCreate() and generic ORM logger

When a SgEntityInfo is created a new global callback onEntityInfoCreate() is
called with the new Entity info object.  SgEntityInfos also store a link to the
schema which the info is built from.

A generic ORM logger ShotgunORM.LoggerORM is available as a general purpose
logger.
added attribs file
Normalize line endings
Tweaked SgFieldInfos repr so that name and label are in quotes
Merge branch 'develop'