Review request: module graph clean up

[Mandy Chung]

Webrev at:
    http://cr.openjdk.java.net/~mchung/jigsaw/webrevs/modules-cleanup.00/

These changes should make the module graph cleaner and separate out some 
components as its own module (currently grouped with some other module):

1) separate java.util.prefs into its own module
2) separate the cosnaming jndi provider as its own module and 
management-iiop as it own module
      - this removes corba's dependency to jndi and management
3) separate management-snmp as its own module
4) remove jdk.ext but break it into sctp, zipfs, httpserver modules
5) rename jsse to ssl

Thanks
Mandy