Certain systems experience memory corruption related to this
effect. There is certainly an underlying bug in effects code
(or SGExpression code), but in the short-term this avoids the
issue by fixing some bad syntax in the .eff file.
(<property> is only for boolean properties, not to read a value)
Switch c172p and concorde glass effects to the new effect.
Docs/model-combined.eff/: Updated transparent effect template.
From now on Effects/model-combined should not be inherited from directly.
Use either Effects/model-combined-deferred
or Effects/model-combined-transparent
Signed-off-by: Emilian Huminiuc <emilianh@gmail.com>