RFR 4947890 : Minimize JNI upcalls in system-properties initialization

[Roger Riggs]

Please review a re-implementation of the initialization of System properties
moving some functions from native to Java.

The upcalls from native to java for each property are replaced by a 
mechanism
to gather the platform, VM and command line properties and return them
from a single JNI call.  The creation of the Properties instance and 
applying
command line overrides is handled in Java instead of native.

The JVM_initProperties interface in Hotspot is replaced by 
JVM_getProperties.

Webrev:
   http://cr.openjdk.java.net/~rriggs/webrev-props-only-raw/

Issue:
   https://bugs.openjdk.java.net/browse/JDK-4947890

Thanks, Roger