Use Keystone Extension Syntax for EC2 Creds
Use Keystone Extension Syntax for EC2 Creds

- Syntax is OS-KSEC2:ec2Credentials (not ec2Credentials)
- adds to fix for bug 917408
- Syntax also requires a call to /tokens instead of /ec2tokens
- Changes are compatible (old syntax supported)
- Warning will be issued to log if URL syntax is old

Change-Id: I5ff9d1643122de2f383517e60f15852720c54490

n0ano/gantt,n0ano/gantt