[DF-278] cubemap textures and skybox for IOS version. Todo: integrate skybox to editor and update macos and win32 projects
[DF-278] Shaders for skybox
Entry poing for adding SkyBox node is implemented in ResourceEditor.
Automatic enable/disable Skybox menu item when the Skybox is added/removed is implemented.
[DF-278] SkyBox changes in order to prepare it for editor integration
Merge remote-tracking branch 'refs/remotes/origin/development_cubemap_integration' into development_cubemap_integration
[DF-278] SkyBox to editor integration
[DF-278] Adding rotation editable property to the SkyBoxNode
Merge remote-tracking branch 'refs/remotes/origin/development' into development_cubemap_integration

Conflicts:
	Sources/Internal/Render/Texture.h
	Tools/ResourceEditor/Classes/Qt/DockProperties/PropertyEditor.cpp
	Tools/ResourceEditor/Classes/SceneEditor/CreateNodesDialog.cpp
	Tools/ResourceEditor/DataQt/mainwindow.ui
[DF-278] Unbinded to scene cube map creation/editing
[DF-278] PVR conversion working for cube maps
[DF-278] DDS compression
Merge remote-tracking branch 'refs/remotes/origin/development' into development_cubemap_integration
[DF-278] tweaks after merge
[DF-278] win32 merged and working
[DF-278] tweaks for UI
[DF-278] final UI tweaks
Merge remote-tracking branch 'refs/remotes/origin/development' into development_cubemap_integration

Conflicts:
	Tools/ResourceEditor/Classes/Qt/Scene/System/HeightmapEditorSystem.cpp
	Tools/ResourceEditor/Classes/Qt/TextureBrowser/TextureConvertor.cpp
	Tools/ResourceEditor/DataQt/mainwindow.ui
	Tools/ResourceEditor/ResourceEditorQt.xcodeproj/project.pbxproj
	Tools/ResourceEditor/ResourceEditorQtVS2010.vcxproj.filters
[Df-278] Merge remote-tracking branch 'refs/remotes/origin/development_cubemap_integration' into development