RFR: JDK-8210958 Rename "make run-test" to "make test"

[Magnus Ihse Bursie]

The time has come to start phasing out the old test running framework 
("cd test && make"). This patch will change the behavior of "make test" 
to use the new run-test framework, instead of the old.

The old framework is still available as of now by using "cd test && make".

The "run-test" target (and variants like exploded-run-test or 
run-test-tier1) are kept as aliases.

Using "cd test && make" will result in a warning being printed that it 
is recommended to stop using this way of running tests.

Bug: https://bugs.openjdk.java.net/browse/JDK-8210958
WebRev: 
http://cr.openjdk.java.net/~ihse/JDK-8210958-rename-run-test-to-test/webrev.01

/Magnus