Release note 2.1

Version 2.1 (Stacks)

Added Stack category. Stack and Unstack islands automatically and manually. Extremely useful for increasing Texel Density and baking. It works using Zen UV Dynamic Library supported on Windows, Mac OS, and Linux platforms.
Added Copy/Paste operators. Copy parameters (TD, Position, Size) between Islands.

Added new operators for UV Editor window.
Added panels management for UV Editor window. Now you can turn off the display of unused categories not only in 3D View but in UV Editor also.
Fixed slowdown of the Main panel when working with large (~500,000 polygons) meshes.

Fixed a bug with disabling Advanced UV Maps panel when Cycles render is selected.

Added Mark Seams By Open Edges operator. Mark all visible Edge Borders as Seams.
Fixed Zen Unwrap operator. The situation when it is impossible to unite two islands, one of which is tagged FINISHED and the other UNFINISHED.
Fixed Mark Seams by UV Borders operator. It now ignores hidden edges.
Fixed Mirror Seams operator.
Updated Display Finished operator. It now uses OSL Shaders instead of Vertex Color and can display Finished Islands and Checker textures simultaneously.
Updated Quadrify operator. The processing time has been significantly reduced.

Added Select Similar Islands operator.
Fixed Select Flipped Islands operator. It now handles n-gons correctly.
Updated Isolate Island operator. It now works in any Blender UV Sync mode. Now you can use it not only in 3D View but in UV Editor also.

Fixed a bug when Reset Checker operator did not restore the texture.
Updated Checker Texture (Toggle) operator. It now uses OSL Shaders instead of Vertex Color and can display Checker Texture and Finished Islands simultaneously.

Added the possibility to measure and set Texel Density in Object mode.
Updated Texel Density operators. The processing time has been significantly reduced.