Removed dependency on Linq in OpenProfileClient
BUlletSim: move safeynet ground plane to lower altitude. Define new BulletSim
parameter 'TerrainGroundPlane' which defaults to -500.

BulletSim had assumed altitudes never went negative but that is not true. The
ground plane is just a safety net so things wouldn't fall to infinity.
BulletSim: non-functional changes to debugging statements and formatting.
Fixed the UpdateAgentInformation CAP: the viewer expects the simulator to echo back the maturity that it sent

Without this change, attempts to change the maturity rating in the viewer's Preferences don't work.
Improved HTTP logging
Add regression test for NPC movement on a variable region.

Extends basic physics to allow av movement on a varregion (basic physics is only really useful for regression test purposes).
Restore terrain height and flying adjustments that were eliminated from non-megaregion paths in ScenePresence.MoveToTarget() by recent patch bc969a6b
minor: convert back some tabs to spaces that got into ScenePresence via recent patch bc969a6b
Add "terrain show" console command which outputs terrain height for a given region co-ordinate.

For debug purposes.
minor: Print output in response to terrain console commands on the console rather than in the log.
minor: Correct mistake in terrain flip error message from previous commit 5d01a1f
Assign value to 'vector' to fix building under xbuild and Monodevelop
Add the "StateChange" function to the async comand manager to differentiate
between state changes and script exit/reset.
Change XEngine to call StateChange rather than RemoveScript on state changes
minor: Use Vector2.Zero constant and only set in condition branch where it was missing in TryParseConsole2DVector().  xbuild still compiles.
Fix issue where only one of multiple attachments on the same attachpoint for NPCs would be seen by other viewers.

It appears that at least Singularity 1.8.5 (but probably others) rely on attachment FromItemIDs being different to display more than one.
This commit resolves this by generating random IDs instead of always using UUID.Zero for NPCs.
Resolves http://opensimulator.org/mantis/view.php?id=7110
Mantis 7144 missing ATTACH_AVATAR_CENTER constant

This patch adds ATTACH_AVATAR_CENTER and ATTACH_NECK
minor: Comment out Cacheitems debug log lines for now
Added a optional key between the group remote connectors, sim and service. This allows for more secure group services, to be used by collections of mutually-trusting grids.
Please note: older simulators (0.7.6) still send the info about gzip in ContentType