RFR 8142926: OutputAnalyzer's shouldXXX() calls return this

[Wang Weijun]

Hi All

8142926: OutputAnalyzer's shouldXXX() calls return this
http://cr.openjdk.java.net/~weijun/8142926/webrev.00/

With this change, you can write output.shouldA().shouldB().shouldC().

Do I need to write a test for testlibrary?

Thanks
Max