Patch for new build to work in jigsaw forest

[Erik Joelsson]

This patch makes the new build compile in the jigsaw forest. It still 
only produces legacy images. Things that needed to be fixed:

Langtools
* excludes for modules in bootstrap javac
* additions to genstubs

Bdb
* Run bdb configure from our configure script
* Call bdb makefile
* Support building with external libdb

JDK
* Import bdb lib into jdk
* Add bdb cflags to libjava compilation
* Copy mapfile-vers file from old build location to new build location

http://cr.openjdk.java.net/~erikj/jigsaw/webrev.bdb-support.01/

I'm not a committer in the jigsaw project, so posting this here. Next I 
will see if I can convert the post modularization procedures to the new 
build.

/Erik