Improved volumetric clouds

Recent changes:

• New volumetric clouds, updated ObjectSky.
• Added Camera object (PlayerDummy node) in UnigineEditor.
• Some renaming in the materials: scattering -> post_scattering, polygon_offset -> offset, priority -> order (don't forget to run upgrade.py script).
• Render performance improvements.
• Added post_deffered flag for the transparent objects (objects with this flag will be rendered into the deffered buffer after rendering into the color buffer), that is useful for water surfaces.
• WidgetSpriteObject is renamed to WidgetSpriteNode and can render the full hierarchy of the node.
• Skinned meshes can be rendered using DirectX 10 stream out feature or OpenGL EXT_transform_feedback extension.
• New type of the particles emitter: shift (particles are generated only if the emitter is moving), that can be used for fake water interaction effect or rocket traces.
• Reduced memory consumption by UnigineScript interpreter.
• Minor improvements of UnigineEditor.
• Correct detection of NVIDIA GTS cards.
• Vegetation animation can be turned off in material settings (less complex shader will be used).
• Fine tuning of volumetric materials' attenuation.
• Support of GL_ARB_texture_rg (optional) and GL_EXT_texture_swizzle (required) extensions.
• Removed support of L and LA image formats (R and RG are used instead).
• Xinerama support (Linux users now can use multi-GPU and multi-screen configurations).
• Added new UpSample material option for transparent objects that reduces their rendering buffer resolution, thus providing performance boost.
• Updated Qt integration sample (now it's compatible with Qt 4).
• Added samples of image manipulations via C++ API.
• Updated documentation: "Console", "Tools / ResourceEditor", "Tools / Plugins for 3D Editors", added info on PSSM into "Technologies Overview / Shadows", added "Programming / Scripts / Input System" article.

There are three surfaces in ObjectSky object now:

• "sphere" provides correct interaction of clouds and sky (clouds can be darker than the sky),
• "clouds" is a new surface for volumetric cumulonimbus clouds (they are simulated by a physically-correct algorithm),
• "shadow" (without changes).

PS: Here is the next step forward we promised recently:Unigine Joins PLAYSTATION®3 Tools and Middleware Program.