* Eliminate CLIInstallerOutput per r68645 since, yes, it wasn't needed.

* Eliminate CLIInstallerOutput per r68645 since, yes, it wasn't needed.
* Make sure output only happens in the top-level Installer implementations.
* Differentiate Status warning messages from Status error messages in the Installer.
* Change abstract method from Install::showStatusError() to Install::showStatusMessage() since we'll use it to show warnings now, too.
* TODO Need a better way to extract/display Status warning messages since, from my look at the Status class, it looks like warnings are implemented, but not really used.