update shell_command.rb to use _pry_.config.system
update whereami command to use _pry_.config.default_window_size.
update 'cat' command to use _pry_.config.default_window_size
update lib/pry/commands/code_collector.rb to use _pry_.config.gist.inspecter.call
update 'edit' command to use _pry_.config.disable_auto_reload
update 'gist' command to use _pry_.config.gist.inspecter