8157598: ModuleReader find returns incorrect URI when modular JAR is a multi-release JAR

[Alan Bateman]

JDK-8151542 changed the URL scheme for resources in the versioned 
section of a multi-release JAR. The ModuleReader API can be used to get 
a URI to a resource in a modular JAR and it needs a corresponding update 
to align with the JEP 238 update. The change is simple:
     http://cr.openjdk.java.net/~alanb/8157598/webrev/

There is still some remaining work to have modular JARs be multi-release 
JARs, jlink mostly, but it is otherwise aligning nicely.

-Alan