Added safe upgrade option and made the mysqldump_tables more robust based on type of mysql db being used and to not expose user/passwords in ps.

Based on a recommendation from jonnyboy, reworked the patching process to do a db backup with the safe option w/o exposing login details and reworked mysqldump_tables to not show user/password in ps. This is achieved by generating a file with the username/password and using the mysqldump --defaults-extra-file parameter to pass the credentials and deleting the file after it is used.