Update forklift to pass the IP address of the containers to other containers

Required for Docker 1.2
Handle the case we can't delete the root tree for some reason
Update postgres container config to load latest container
Update services to pass in host of child container
Add a comment explaining why data_dir is commented out

[skip ci]
Merge pull request #70 from infoxchange/fixes

Fixes
Merge branch 'master' into url-service

Conflicts:
	forklift/services/base.py
	forklift/services/postgres.py
	forklift/services/redis.py