Various installation fixes

02-SubscriptionManagement: Switch from RHN to RHSM.

03-Installation: Recommend GNU Screen.

04-VerifyInstall: Delete ActiveMQ (Jetty) console; fix typo.

06-AddingCartridges: Delete reference to bundle; mention oo-admin-yum-validator, oo-admin-cartridge, cartridge repository, restarting ruby193-mcollective, and oo-mco diagnostic check.