milestone list formatting

See discussion in gh-157. Current output should look like: 
```
2014-04-10 09:21:44,792 [scc.mileston] INFO  Repository: openmicroscopy/openmicroscopy
                NAME              CREATED                  DUE   OPEN CLOSED
               5.0.2  2014-04-08 06:54:56  2014-04-30 07:00:00      0      0
               5.0.3  2014-04-08 06:55:44  2014-05-31 07:00:00      0      0
               5.0.4  2014-04-08 06:55:59  2014-06-29 07:00:00      0      0
               5.1.0  2013-12-19 14:41:49                           0     41
2014-04-10 09:21:45,429 [scc.mileston] INFO  Repository: openmicroscopy/bioformats
                NAME              CREATED                  DUE   OPEN CLOSED
               5.1.0  2013-12-19 14:42:19  2014-03-31 07:00:00      0      0
               5.0.2  2014-04-08 06:54:57  2014-04-30 07:00:00      0      0
               5.0.3  2014-04-08 06:55:45  2014-05-31 07:00:00      0      0
               5.0.4  2014-04-08 06:56:00  2014-06-29 07:00:00      0      0
2014-04-10 09:21:46,047 [scc.mileston] INFO  Repository: ome/scripts
                NAME              CREATED                  DUE   OPEN CLOSED
               5.1.0  2013-12-19 14:43:30  2014-03-31 07:00:00      0      0
               5.0.2  2014-04-08 06:54:58  2014-04-30 07:00:00      0      0
               5.0.3  2014-04-08 06:55:46  2014-05-31 07:00:00      0      0
               5.0.4  2014-04-08 06:56:01  2014-06-29 07:00:00      0      0
2014-04-10 09:21:46,661 [scc.mileston] INFO  Repository: openmicroscopy/ome-documentation
                NAME              CREATED                  DUE   OPEN CLOSED
               5.1.0  2013-12-19 14:43:04  2014-03-31 07:00:00      0     17
               5.0.2  2014-04-08 06:54:58  2014-04-30 07:00:00      0      0
               5.0.3  2014-04-08 06:55:46  2014-05-31 07:00:00      0      0
               5.0.4  2014-04-08 06:56:01  2014-06-29 07:00:00      0      0
```
Suggestions welcome.