Document how to exit "python-interactive"

[Eli Zaretskii]

> From: Khoo Yit Phang <khooyp@cs.umd.edu>
> Date: Thu, 23 Aug 2012 13:47:35 -0400
> Cc: Eli Zaretskii <eliz@gnu.org>, gdb-patches@sourceware.org
> 
> Here's the updated patch. I made one other minor change from "Python interactive prompt" to "interactive Python prompt" for consistency. Does it look good?

Almost.

> -Start a Python interactive prompt.\n\
> +Start an interactive Python prompt.  To return to GDB, type the EOF\n\
> +character (e.g., Ctrl-D on an empty prompt).\n\

I still think the first line should have only one sentence.  This is
how we write doc strings everywhere else.

Thanks.