refactor: Make AttachmentModulesTests.TestSameSimulatorNeighbouringRegionsTeleportV2 use already available TestClient handle rather than retrieving it via the ScenePresence
Add TestSameSimulatorNeighbouringRegionsV2() regression test for v2 entity transfer protocl
Add ScenePresenceTeleportTests.TestSameSimulatorIsolatedRegionsV2() regression test for v2 transfers.

Also adjusts names of teleport setup helpers in EntityTransferHelpers
Fix issues with RemoteAdmin admin_save_heightmap and admin_load_heightmap not working.

This is because they were wrongly looking for both regionid and region_id parameters in the same request.
Now only region_id is required (and recognized), regionid having been already deprecated for some time.
This is essentially Michelle Argus' patch from http://opensimulator.org/mantis/view.php?id=6737 but with tabs replaced with spaces.
Thanks!
minor: Make log messages consistent in NeighbourServicesConnector
minor: remove mono compiler warning in StatsManager
remove mono compiler warnings from PollServiceRequestManager
minor: remove mono compiler warnings from ScenePresence
minor: remove mono compiler warnings from OpenSim/Services/Connectors/SimianGrid
Remove some mono compiler warnings from OpenSim/Server/Handlers
minor: remove mono compiler warning from AttachmentsModule
Remove mono compiler warnings from UserProfilesModule