Cleanup help strings and docs for clarity and to keep things consistent:
* --limit metavar should be <num-resource> to indicate what is being counted
* --marker metavar should be <resource> or <resource-id> to indicate the
type of value being specified
* <*-ip-address> metavars should be just <ip-address> as there is no difference
in format between fixed and floating IPs
* Move all occurances of '(name or ID)' to end of help text
Change-Id: I2c31746ed6ded3845244e03e57d809f8bc0e6b9d
1686dc54f0