Fix recent regression where an item worn to an attachment point that was already occupied did not remove the previous attachment (current behaviour)

Regression was commit ccd6f4 (Tue Mar 5 23:47:36 2013)
Added regression test for this case.
Improve rejection of any attempt to reattach an object that is already attached.

This also adds/extends regression tests for wearing attachments directly for the scene and attempting to reattach/rewear already attached objects.
Multiattach, part 1

Conflicts:

	OpenSim/Framework/AvatarAppearance.cs
	OpenSim/Region/CoreModules/Avatar/Attachments/AttachmentsModule.cs
	OpenSim/Region/CoreModules/Avatar/Attachments/Tests/AttachmentsModuleTests.cs
	OpenSim/Region/Framework/Interfaces/IAttachmentsModule.cs
	OpenSim/Region/Framework/Scenes/Scene.cs
	OpenSim/Region/OptionalModules/Avatar/Attachments/TempAttachmentsModule.cs
	OpenSim/Region/ScriptEngine/Shared/Api/Implementation/LSL_Api.cs
Multiattach, part 2
Limit each attachment point to 5 items as per spec
Merge commit 'ccd6f443e1092cb410f565e921f7cf4dd8cd2dac' into newmultiattach

Conflicts:
	OpenSim/Region/CoreModules/Avatar/Attachments/AttachmentsModule.cs
Merge branch 'master' into newmultiattach

Conflicts:
	OpenSim/Region/CoreModules/Avatar/Attachments/AttachmentsModule.cs
Fix tests for multiattach
Process default attachment point in AttachObjectInternal before we check whether a worn object needs to displace an existing attachment on the same point if we are not using multi-attach.
BulletSim: add terrain contact processing threshold parameter. Initialize contact processing threshold for static object as well as mesh terrain.
BulletSim: code to generate a higher resolution terrain mesh. Parameter
TerrainMeshMagnification controls number of vertices generated per
heightmap point. Default is 3.
For those people collecting and comparing logfiles from servers scattered
around the world, change LogWriter to use DateTime.UtcNow rather than
DateTime.Now.
For the moment, disable the output of the 'scene' statistics in SimExtraStatsCollector
and thus for the command 'show stats' because it is ugly and most of the information
is already output in the formatted printout that appears before.
Prevent multiple instances of the same item ID being appended to an AvatarAppearance

It looks like this was happening when AttachmentsModule.RezAttachments was doing a secondary set of each attachment to update with the asset ID (initially they only have the inventory ID).
However, with multi-attach this was appending a second copy of the same attachment rather than updating the data that was already there.
This commit requires both simulator and service to be updated.
BulletSim: change 'degenerate mesh' message from Error to Debug because there
seem to be lots of sculpties with this problem while the condition really doesn't
change region operation.
Merge branch 'master' of ssh://opensimulator.org/var/git/opensim
Force a viewer object update for attachments at the end of the final Scene.CompleteMovement() in order to make all multi-attachments appear on the destination region.

For some reason, sending updates before this will not have this effect.
This may be something related to some viewers (e.g. LL 3.3.4) or something OpenSimulator isn't getting quite right.
Fix "show attachments" command probably broken in commit addab12 (Wed Jan 2 21:38:00 2013)

This break was not connected with the recent attachment code changes.
Insert a short delay on the simulator side rezzing of attachments in order to fix viewer 3 issues if its own rezzing actions on login collide with the simulator side actions.

This resolves issues (at least in my tests with LL 3.3.4) where this can make attachments invisible until one zooms in on the avatar.
This doesn't affect version 1 viewers since this delay is shorter than the login delay.
This doesn't increase the login time since this part of the process was already being performed asynchronously.
This may be a temporary solution.
On the later forms of teleport failure, tell the user if this was because viewer couldn't/didn't connect with destination or if destination didn't signal teleport completion.

Also adds regression test for the case where the viewer couldn't connect with the destination region.
Also refactoring of regression test support code associated with entity transfer in order to make this test possible and the code less obscure.