Implement building openjdk8 with openjfx8

For example:

XUSE_NEW_BUILD_SYSTEM=true XBUILD=true  XUSE_TAG=jdk8-b132 XUSE_JFX_TAG=8.0-b132 XGRADLE=/usr/lib/gradle/1.9/bin/gradle  ./obuildfactory/openjdk8-javafx/linux/standalone-job.sh

This builds openjdk8 _and_ openjfx8 including all native libraries.  This basicly merges https://wiki.openjdk.java.net/display/OpenJFX/Building+OpenJFX#BuildingOpenJFX-BuildandTest into the build.