* Remove credential creation from files/keystone_data.sh
* Remove EC2 cert setup from openrc
* Remove sourcing of ec2rc from stackrc
* Collect the above in eucarc
* Allow rc files to be sourced from other directories; based on Chmouel's
4881 proposal but is simpler and doesn't actually change the directory
* Create S3 endpoint
* Get EC2 and S3 endpoints from Keystone service catalog
* Add EC2 credential checks to exercises/client-env.sh
* exercises/bundle.sh and exercises/euca.sh use eucarc
Updates:
* remove readlink -f to stay bash 3 compatible
* use service catalog
* create S3 endpoint
Fixes bug 949528
Change-Id: I58caea8cecbbd10661779bc2d150d241f4a5822e