[9] RFR: 8166530: sun/net/www/protocol/https/HttpsClient/ProxyAuthTest.java fails intermittently

[Artem Smotrakov]

Hello,

Please review the patch below for 
sun/net/www/protocol/https/HttpsClient/ProxyAuthTest.java test.

The test has been observed to fail intermittently, but the failure is 
not reproducible standalone. The patch updates the test to follow the 
approach from SSLSocketSample.java

http://hg.openjdk.java.net/jdk9/dev/jdk/file/1f044f413e6c/test/javax/net/ssl/templates/SSLSocketSample.java

I merged OriginServer.java to ProxyAuthTest.java since only this test 
uses that file. I also added a couple of new common methods to 
SSLTest.java. They are not used by ProxyAuthTest.java, but can be useful 
in other tests.

Bug: https://bugs.openjdk.java.net/browse/JDK-8166530
Webrev: http://cr.openjdk.java.net/~asmotrak/8166530/webrev.00/

Artem