RFR JDK-8152206: Simplify jvmstat modules

[George Triantafillou]

Please review this fix for JDK-8152206.  The module jdk.jvmstat.rmi was 
renamed to jdk.jstatd.  All tests and makefiles were updated with the 
new module name.

JBS Bug: https://bugs.openjdk.java.net/browse/JDK-8152206
Open Webrevs:

http://cr.openjdk.java.net/~gtriantafill/8152206/webrev/top/webrev/ 
<http://cr.openjdk.java.net/%7Egtriantafill/8152206/webrev/top/webrev/>
http://cr.openjdk.java.net/~gtriantafill/8152206/webrev/jdk/webrev/ 
<http://cr.openjdk.java.net/%7Egtriantafill/8152206/webrev/jdk/webrev/>
http://cr.openjdk.java.net/~gtriantafill/8152206/webrev/hotspot/webrev/ 
<http://cr.openjdk.java.net/%7Egtriantafill/8152206/webrev/hotspot/webrev/>

The fix was tested with the hotspot_all test group on Linux x64. Thanks.

-George