[8u40] Review request for 8065702+8065675 Deprecate the Endorsed and Extension Mechanisms

[Mandy Chung]

This is to request review and approval to putback these spec changes
in 8u40.
   JDK-8065702  Deprecate the Extension Mechanism
   JDK-8065675 Deprecate the Endorsed-Standards Override Mechanism

The endorsed and extension mechanisms are proposed to be removed
in JDK 9 [1].  This patch updates the following specifications:

1. javadoc of System.getProperties to deprecate  "java.ext.dirs"

2. deprecate three fields injava.util.jar.Attributes.Names
    EXTENSION_INSTALLATION
    IMPLEMENTATION_VENDOR_ID
     IMPLEMENTATION_URL

3. deprecate the ability of a JAR-packaged applet to depend on
    an installed optional package and trigger downloading of
    optional packages and its relevant attributes

TheMaintenance Review of JSR 337 (Java SE 8) will indicate the
above spec changes.  There is no implementation change in this
patch.

The specification of the Class-Path attribute and Sealed attributes
are misplaced and they should belong to the JAR file specification.
This patch moves them from extensions to the JAR file specification.

Webrev at:
http://cr.openjdk.java.net/~mchung/jdk8u/webrevs/8065702/webrev.00/
http://cr.openjdk.java.net/~mchung/jdk8u/webrevs/8065702/api-diff/overview-summary.html
http://cr.openjdk.java.net/~mchung/jdk8u/webrevs/8065702/specdiff/overview-summary.html

Mandy
[1] http://openjdk.java.net/jeps/220
[2] http://openjdk.java.net/projects/jdk8/spec/