Add feature to copy to X clipboard #234

Enable copying the current buffer directly into the X clipboard. I've a attached a diff that implements this by using the "xclip" external program. Works for me, but you may have other ideas.

• Bitbucket: https://bitbucket.org/bobf/bpython/issue/234
• Originally Reported By: Anonymous
• Originally Created At: 2012-11-15T06:42:11.520