Correct sync of new region commands, drop XML2 commands

* Dropped Xml2 commands after further investigation, OAR's are a better
alternative and it does not appear that the XML2 format is in common
use with OpenSim anyway

* SceneManager
    - Re-synced new Region commmads after a stuff up in doing so
previously
    - Add port to 'Show regions' command

* FileBasedSimulationData
    - Correct some problems in the 'update region info' command