todo task for gci and bug fix

I don't think there's a need for a table for documents. Documents is used as a component in a lot of places, and can be used as a super entity. 
eg: https://github.com/flavour/eden/blob/master/private/templates/SSF/config.py#L342
https://github.com/flavour/eden/blob/master/modules/s3db/project.py#L155
What you've done is for defining components for a specific resource, that might not be used in several other places..
Look here as well http://eden.sahanafoundation.org/wiki/S3/S3Model/SuperEntities