instance-action-list output field and order is not human-friendly

instance-action-list is output only contents of the specified instance actions now.
But it is not possible to identify the order and time.

Examples of current:
$ nova instance-action-list server-001
+-------+------------------------------+---------+
| Action | Request_ID | Message |
+-------+------------------------------+---------+
| create | req-528a4dd4-f0d2-49d3-9de4-601eb2b64171 | None |
| pause | req-10309a20-e994-4f70-9901-11b6531b0854 | None |
| pause | req-1897f82b-602a-4912-bf2e-de6df14a7a71 | None |
| reboot | req-f084c9ca-acbd-4803-a195-4604b77e9017 | None |
| resume | req-800829c0-3438-4219-8d36-d43115498f1e | None |
| start | req-bb15500e-27eb-4234-a045-30e108bd51be | None |
| stop | req-e6bac5d0-193f-4113-b6e2-4dd53d11e1fc | None |
| suspend | req-711fced2-2f3e-446d-b9fa-11e47a663bef | None |
| unpause | req-56a7ce5e-3dc9-475d-b75a-24f7a30bf93f | None |
| unpause | req-c42eb0f3-f8a7-4ed1-b755-b0703bf35db0 | None |
+-------+------------------------------+---------+

Examples of improvement:
$ nova instance-action-list server-001
+-------+------------------------------+---------+--------------------+
| Action | Request_ID | Message | Start_Time |
+-------+------------------------------+---------+--------------------+
| create | req-528a4dd4-f0d2-49d3-9de4-601eb2b64171 | None | 2013-04-17T08:37:03.000000 |
| pause | req-10309a20-e994-4f70-9901-11b6531b0854 | None | 2013-04-17T20:46:25.000000 |
| unpause | req-c42eb0f3-f8a7-4ed1-b755-b0703bf35db0 | None | 2013-04-18T07:46:30.000000 |
| pause | req-1897f82b-602a-4912-bf2e-de6df14a7a71 | None | 2013-04-18T11:49:35.000000 |
| unpause | req-56a7ce5e-3dc9-475d-b75a-24f7a30bf93f | None | 2013-04-18T12:49:39.000000 |
| reboot | req-f084c9ca-acbd-4803-a195-4604b77e9017 | None | 2013-04-18T16:00:04.000000 |
| stop | req-e6bac5d0-193f-4113-b6e2-4dd53d11e1fc | None | 2013-04-18T19:59:38.000000 |
| start | req-bb15500e-27eb-4234-a045-30e108bd51be | None | 2013-04-19T07:59:58.000000 |
| suspend | req-711fced2-2f3e-446d-b9fa-11e47a663bef | None | 2013-04-19T12:01:14.000000 |
| resume | req-800829c0-3438-4219-8d36-d43115498f1e | None | 2013-04-19T13:03:19.000000 |
+-------+------------------------------+---------+--------------------+