Summary
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Remove the java.awt.graphicsenv system property

Problem
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  The java.awt.graphicsenv system property has been used since JDK 1.2 to specify the concrete platform implementation class for the abstract SE API class java.awt.GraphicsEnvironment.
This not only pollutes the system property space, but implies that this is pluggable which it is not. Nor was it ever considered a "standard" system property but it used the "java" namespace. 

Also the code that sets it is embedded into the launcher which is also undesirable creating a cross-module dependency  whereby
the launcher has hard-coded the names of internal implementation classes of the desktop module.

Solution
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Remove the java.awt.graphicsenv system property
 which is used to specify the name of the platform implementation class.

It is replaced by a mechanism entirely internal to the java.desktop module.

Specification
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Remove the java.awt.graphicsenv system property