Support keyring for the api_key
Support additional attributes that would allow the rax modules to work with other OpenStack clouds
identity_type is set dynamically above
Support using ~/.pyrax.cfg and multi environments
Only specify to USE_KEYRING as the api_key/password when we actually got a keyring_username from ~/.pyrax.cfg
Make sure to also include the region when using keyring_auth
Support providing a tenant_name also
Update rax module DOCUMENTATION with new auth options
Merge pull request #5806 from sivel/rax-mod-utils-improvements

Rax mod utils improvements