[OpenJDK 2D-Dev] RFR: Fix for 8027541: Fully transparent jframe becomes black.

[Phil Race]

http://cr.openjdk.java.net/~prr/8027541/

In the case where there is an alpha color on the window, the
X11 pipeline looks at the color model of the GraphicsConfiguration
and upgrades the surface to one with alpha. This makes the Xrender
pipeline do the same. SQE test failure, so no regression test needed
in this case.

-phil.