Added assembly config for renjin-script-engine

Additional artifacts are now availble for "non-Maven"
developers:
  renjin-script-engine-VERSION-bin.zip - includes all dependencies
     as individual jars in a zip file
  renjin-script-engine-VERSION-jar-all-dependencies.jar - fat jar
     with all dependencies merged into a single jar
Merge branch 'master' of github.com:bedatadriven/renjin