Create subpackage that only contains the jar files

Hello nicks, 

Please review the following commits I made in branch 'dpup'.

c0e73d0ff34193fe82b2d15e662f54347d45cf20 (2013-04-03 08:39:47 -0700)
Create subpackage that only contains the jar files
The sub-package will be what soynode depends on, via the package
version.  Plovr can continue to bring in the source directly. We
can publish the sub-package to NPM

R=nicks