v0.9.11.1 bugfix

* forgot to remove 'no_arg' from Pry::Command::CodeCollector, this method no longer exists
and so 'gist' (when not given any params) would break. Replaced no_arg with empty string ""
so that 'gist' gists current object/method by default.
updated CHANGELOG for 0.9.11.1
gist: window's fix for broken clipboard