JDK 10 RFR of JDK-8173905: Test tools/jar/multiRelease/RuntimeTest.java fails under JDK 10

[Amy Lu]

After the version update to "10" in JDK 10 ( JDK-8029942 ), test 
tools/jar/multiRelease/RuntimeTest.java starts failing because the 
release version is hardcoded, not only in the test itself, but also in 
test data files for the jar that tested on.

I've updated the test to generate those data files on the fly based on 
the template and $version, and the hardcoding of release version also be 
replaced by the value based on Runtime.version().major(). In this way, 
test don't need to be updated again for JDK 11.

Compared the newly generated "data" files with the old "data", no diff 
(except the version).

bug: https://bugs.openjdk.java.net/browse/JDK-8173905
webrev: http://cr.openjdk.java.net/~amlu/8173905/webrev.00/

Tested on all platforms.

Thanks,
Amy