Sibl-gui

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- Implemented **Softimage_VRay_Standard** Template.

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- Ensured **Softimage_Arnold_Dome_Light** and **Softimage_Arnold_Standard** Templates are compatible with **SItoA** 2.6.0 and the **utility** shader categorie change.

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- Fixed **Softimage_MR_Standard** template issue related to **mia_physicalsun** shader intensity being affected by **Ibl_Feedback** rotation.

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- Dropped support for **XSI_Arnold_Dome_Light**, **XSI_Arnold_Standard** and **XSI_MR_Standard** Templates.
- Dropped support for **3dsmax** versions prior to **3dsmax 2010**.
- Dropped support for **Maya** versions prior to **Maya 2011**.
- Disable **mentalrayGlobals.passAlphaThrough** attribute in **Maya_MR_Standard** and **Maya_MR_Lightsmith** Templates.

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- Refactored **Maya_Arnold_Standard** Template.
- Added **Maya_Arnold_Dome_Light** Template.

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- Added support for shadow catching ground in **Arnold XSI / Softimage Templates**.