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

[A. Sundararajan]

Please review http://cr.openjdk.java.net/~sundar/8009115/
Changing javax.script tests to use nashorn engine explicitly - also 
adjusting tests to reflect (minor) changes b/w nashorn and rhino.

Thanks
-Sundar