docencoding not available to stylesheet

[jayashree viswanathan]

*Problem statement : *Stylesheet.css is not getting encoded like the 
other generated html files while using -docencoding

*Recreation step : *
javadoc -docencoding "use non-ascii encoding" HelloWorld.java
say ,
jdk1.8.0\bin\javadoc.exe -docencoding Cp930 -d docencoding3 HelloWorld.java

*Explanation :*
The stylesheet.css is not getting generated in the proper encoding as in 
the code the configuration.docencoding is not getting passed to the 
output stream .
while this scenario works in JDK 6 [as confirmed in Java 6u14] , below 
changeset seems to have regressed this when adding new copyFile method.

Changeset:
792 (ffbf2b2a8611) 7006270: Several javadoc regression tests are failing 
on windows

Please find the webrev patch with changes and jtreg test .

http://cr.openjdk.java.net/~luchsh/ojdk-660/

Thanks and Regards,
Jayashree V