Mesh Limits test

=Scope=
The scope of this test is to identify limits for uploading mesh assets and confirm that the viewer provides expected error messages and fails gracefully when those limits are exceeded.
=Test=
===Maximum Import Model Size Test===
* The maximum mesh asset size after compression is 8MB, roughly equivalent to a 256MB raw COLLADA file. An entire region can support up to 128MB of distinct mesh assets after compression, not including attachments. The size of attached mesh assets is effectively unlimited, but there's no guarantee that all of your attachments will be downloaded by other viewers.
* Confirm that importing models of various sizes up to 256 MB COLLADA files succeeds without error in the viewer
* Confirm that attempting to import a COLLADA file exceeding 256 MB is not allowed by the viewer and a descriptive error message is given explaining the limit in the viewer. (Need to obtain models to test this)
===Maximum Number of Meshes Per Model Test===
* There is no maximum number of meshes per import. However anything greater than 15,000 meshes would not be able to be rezzed inworld.
* The maximum asset size to import is 8 MB so this would be tested by testing the Maximum Import Model size above.
===a single convex hull is limited to 256 triangles===
* How do I attempt to upload a 257 triangle mesh?
* As a mesh's convex hull can be set to be any of its LoD levels, including the highest, a convex hull is not necessarily limited to 256 triangles.
* A shape which presents many concave surfaces however (such as branches on trees or bowls) will be subject to decomposition into multiple convex hull shapes.
===a decomposition cannot have more than 256 hulls===
* How do I attempt to create or upload a 267 hull decomposition? 
===Maximum Number of Triangles===
* There is not a maximum # of triangles a model can have, however the number of vertices is limited to 65,536.
* Confirm that importing models with up to 65,536 vertices works without error (assuming no other limits are exceeded - 8 MB asset size)
* Confirm that attempting to import a model that exceeds 65536 vertices fails and a descriptive error message is given in the viewer outlining the limit. (Need to obtain models to test.)
===Import Mesh Scale Limit Test===
* The scale limit is set to 64 M
* Confirm a model cannot be imported exceeding 64 M on an axis. 
* Confirm when setting the scale in the modifiers tab in the upload model dialog, entering a scale that will exceed this 64 on an axis will automatically adjust the scale value to the maximum allowed with an axis not exceeding 64 meters. 
===Maximum Mesh Scene Scale Limit Test===
* The maximum dimensions of a mesh scene can only be 240m on a side. Larger than this will (as of viewer 3.0.0 (238864)) will frequently cause crash to desktop errors, or a notice that the mesh is larger than "256m"
* Release notes specified this change to fix a server issue, possibly will be corrected later?
* While the upload dialog does not specify a Z dimension, only X and Y dimensions, it does still check the Z axis for its overall length
===Uploaded meshes are linked to each other when they are within link distance===
===Uploaded meshes are coalesced to each other when they are farther apart than link distance===
===Upload Texture Limits===
Are there any limits?
===Rigged Mesh Limits===
Are there any limits, such as maximum size of the skeleton?
Size follows the same limits for non-rigged mesh. (ie:64m x 64m x 64m)