Completely remove the methods deprecated by last few commits:
* DB#disable_binary_logging and DB#enable_binary_logging now raise an exception
* DB#mysql_config_file removed
* Host#comment_out_ini removed
* Host#uncomment_out_ini removed
* Host#toggle_ini removed

Overall the approach of editing config files is just too brittle,
especially given that config files are usually handled by a configuration
management tool (puppet, chef, cfengine, etc) which can easily clobber
the changes if you forget to disable it.
More output regarding what options in use for DB#start_mysql and DB#restart_mysql