Fix issues found with new version of CommandLauncherFactory extension

- have setLanguageSettingEntries() and getLanguageSettingEntries()
  methods look for best factory to use (one that has highest
  priority) which matches getCommandLauncher() logic
- fix loadCommandLauncherFactoryExtensions() typo

Change-Id: I524a41727778c4d0235bdcc9d28d74d44a02f1f6
Signed-off-by: Jeff Johnston <jjohnstn@redhat.com>