Leading and training colon should not be included in scanned copyrights

For instance scanning this:

```
    :copyright: (c) 2013 by Armin Ronacher.
    :license: BSD, see LICENSE for more details.
```

yields:
`:copyright: (c) 2013 by Armin Ronacher.`
instead of:
`copyright (c) 2013 by Armin Ronacher.`
