Leading and training colon should not be included in scanned copyrights

[pombredanne]

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.