hg: jdk9/dev: 8172312: Update docs target and image for new combined docs

[magnus.ihse.bursie at oracle.com]

Changeset: 566474d7b2e0
Author:    ihse
Date:      2017-04-19 10:24 +0200
URL:       http://hg.openjdk.java.net/jdk9/dev/rev/566474d7b2e0

8172312: Update docs target and image for new combined docs
Reviewed-by: erikj, mchung
Contributed-by: Magnus Ihse Bursie <magnus.ihse.bursie at oracle.com>, Mandy Chung <mandy.chung at oracle.com>

! make/Javadoc.gmk
! make/Main.gmk
! make/common/MakeBase.gmk
! make/common/Modules.gmk