Filter endpoints by region whenever possible

Previously, the endpoints command just returned the first endpoint. This
was not very useful; people expected to see the endpoints in the region
they specified. This patch does the following:

- If there's only one endpoint, use that.
- If there's a specific one for your region, use that.
- If there isn't, warn, and show the other ones.

Closes-Bug: #1256009
Change-Id: I70b82bdffb9b2e3da415a3bb941bcff287e39789
fix host resource repr to use 'host' attribute

This change fixes an AttributeError raised when attempting to
represent a host resource as a string.

Change-Id: I33369b20ed7f5219c3b507107b8f3a37b46eacee
Closes-Bug: #1327005
Fix rxtx_factor name for creating a flavor

On v3 API, rxtx_factor parameters has been renamed to
'os-flavor-rxtx:rxtx_factor' for consistent interfaces.
This patch applies it to 'nova flavor-create' command.

Closes-Bug: #1350022
Change-Id: I49e24f0220f87616f346f36973312b2f29333841
Merge "Filter endpoints by region whenever possible"
Merge "fix host resource repr to use 'host' attribute"
Merge "Fix rxtx_factor name for creating a flavor"