8023454: Updated DEVELOPER_README and command line flags, ensuring that undocumented flags that aren't guaranteed to work (disabled by default) and that are work in progress show up with an EXPERIMENTAL tag.
Reviewed-by: attila, jlaskey
# This file identifies the root of the test-suite hierarchy.
# It also contains test-suite configuration information.
# DO NOT EDIT without first contacting jdk-regtest@sun.com.
# The list of keywords supported in the entire test suite
keys=2d dnd i18n