* Add Status::getWarningsArray() to complement Status::getErrorsArray()

* Add Status::getWarningsArray() to complement Status::getErrorsArray()
* Add Status::getWikiTextArray() to allow different ways of formating a bunch of status messages (e.g. CLI output)
* Clean up messages in CliInstaller, use more i18n
* Use warning messages from Status return object in CLI installer
* Make Installer::isCompiled static so we don't have to create an object just to see that we can't use it.
* Add Installer::addInstallStepFollowing so we don't have MySQLInstaller mucking in its parent's data