Review request for 8009115: jtreg tests under jdk/test/javax/script should use nashorn as script engine

[A. Sundararajan]

Hi,

Please review http://cr.openjdk.java.net/~sundar/8009115/

Changing javax.script tests to use nashorn engine explicitly. Adjusted 
tests for differences b/w nashorn and rhino engines.
Changes documented here: http://cr.openjdk.java.net/~sundar/8009115/README

Thanks
-Sundar