build updates

[Alan Bateman]

Just a quick note to say that the changes that I just pushed (on behalf 
of Erik) get jigsaw/jigsaw building the regular JRE/JDK images with the 
new build. The next step will be to add the a "modules" target that 
works like the post-processing step in the old build and gives us module 
image + jmods. Hopefully we'll have that soon and that will eliminate 
our dependency on the old build. More medium term is of course to 
restructure the source code and have the build compile modules directly.

The other module configuration changes from a few days ago are just to 
update the configuration as there have been a lot of changes in jdk8 
since we last updated it.

-Alan