v2.0.6-beta

This release contains the changes from v2.0.5b alongside some additional fixes and improvements.

Changes:

• $detail additive is always used instead of $selfillum for better consistency, and emission is now gamma-corrected to match Strata PBR.
• When phong is not being used, the envmap mask will be multiplied to compensate.
• Fresnel parameters are now included in the vmt to improve the look of overly-shiny surfaces.
• A new phong-only mode has been added, which acts similarly to Model: Envmap+Phong but with the envmap-related properties disabled.

Fixes:

• The window icon has been fixed for all platforms.
• The window display text has been reverted for consistency on Windows.