RFR: 8217605: Add support for e-paper displays

[John Neffenger]

Please review the changes for "Add support for e-paper displays."

   https://bugs.openjdk.java.net/browse/JDK-8217605
   https://github.com/javafxports/openjdk-jfx/pull/369

The "18 changed files with 3,622 additions and 2 deletions" reported by 
GitHub breaks down into the following actual lines of code (as measured 
by "cloc"):

   1,014 Java source code
     287 Java unit test code
     405 C source code
     120 C header file
   -----
   1,826 total lines of code

Only two existing files were modified. I added nine lines in 
"armv6hf.gradle" to include the Monocle EPD Platform in the build, and 
one line in "addExports" to allow the new unit test programs to run.

   buildSrc/armv6hf.gradle
   modules/javafx.graphics/src/test/addExports

I'll make some videos of my JavaFX test application to demonstrate the 
features of the new platform.

Thank you,
John