CLI info command

The info command displays metadata about a blob:

```sh
$ doss info 1
ID		1
Created		Wed Jul 17 12:53:32 EST 2013
Modified	Wed Jul 17 12:53:32 EST 2013
Accessed	Wed Jul 17 12:53:42 EST 2013
Size		24.1 KB
```

Which can be handy.   This is part of nla/doss/issues/5.