Add limits to V3 and improve limits formatting in shell

Adds support for the limits API to the v3 client.

Also improve the formatting of absolute-limits from

+-------------------------+-------+
| Name                    | Value |
+-------------------------+-------+
| maxServerMeta           | 128   |
| maxPersonality          | 5     |
| maxImageMeta            | 128   |
| maxPersonalitySize      | 10240 |
| maxTotalRAMSize         | 51200 |
| maxSecurityGroupRules   | 20    |
| maxTotalKeypairs        | 100   |
| totalRAMUsed            | 512   |
| maxSecurityGroups       | 10    |
| totalFloatingIpsUsed    | 0     |
| totalInstancesUsed      | 1     |
| totalSecurityGroupsUsed | 1     |
| maxTotalFloatingIps     | 10    |
| maxTotalInstances       | 2     |
| totalCoresUsed          | 1     |
| maxTotalCores           | 20    |
+-------------------------+-------+

to

+--------------------+------+-------+
| Name               | Used | Max   |
+--------------------+------+-------+
| Cores              | 1    | 20    |
| FloatingIps        | 0    | 10    |
| ImageMeta          | -    | 128   |
| Instances          | 1    | 2     |
| Keypairs           | -    | 100   |
| Personality        | -    | 5     |
| PersonalitySize    | -    | 10240 |
| RAM                | 512  | 51200 |
| SecurityGroupRules | -    | 20    |
| SecurityGroups     | 1    | 10    |
| ServerMeta         | -    | 128   |
+--------------------+------+-------+

Change-Id: I93a456b402aeba8e39480567edb090cbb1898d16
Merge "Add limits to V3 and improve limits formatting in shell"