8008662: Add @jdk.Supported to JDK-specific/supported API

[Alan Bateman]

Joe Darcy recently added @jdk.Supported [1] to make it possible to 
identify JDK-specific APIs.

I'd like to add this to a number of APIs in the com.sun namespace to 
make it obvious these are "supported".  Specifically I'm proposing to 
add it to:

- Java Debug Interface (com.sun.jdi)
- Attach API (com.sun.tools.attach)
- SCTP API (com.sun.nio.sctp)
- HTTP server API (com.sun.net.httpserver)
- Management extensions (com.sun.management)
- JDK-specific API to JAAS (com.sun.security.auth)
- JDK-specific JGSS API (com.sun.security.jgss)

The javadoc for all of these is generated as part of the regular JDK 
"docs" build and so shouldn't be controversial. There are a number of 
other candidates in com.sun with murkier status that I've stayed clear 
of for now.

The webrev with the changes is here:

http://cr.openjdk.java.net/~alanb/8008662/webrev/

In a couple of cases the package description is legacy package.html so 
I've had to move/convert them to package-info.java.

In all but one case I've added the annotation to the package-info, the 
one exception is com.sun.management where there is at least one type 
that is documented as "not supported". Joe Darcy might have suggestions 
on that.

Otherwise this is mostly mechanical and the patch file is easier to 
review that the webrev.

-Alan

[1] http://hg.openjdk.java.net/jdk8/tl/langtools/rev/55cca2f38ee6