Now exits with an error code if the packing failed. Also fixed a bug where it wasn't heeding the command-line arguments.
Now exits with an error code if the packing failed. Also fixed a bug where it wasn't
heeding the command-line arguments.

fhieber/incubator-joshua,fhieber/incubator-joshua,fhieber/incubator-joshua,lukeorland/joshua,kpu/joshua,thammegowda/incubator-joshua,lukeorland/joshua,gwenniger/joshua,thammegowda/incubator-joshua,gwenniger/joshua,kpu/joshua,lukeorland/joshua,kpu/joshua,gwenniger/joshua,lukeorland/joshua,kpu/joshua,thammegowda/incubator-joshua,thammegowda/incubator-joshua,fhieber/incubator-joshua,lukeorland/joshua,thammegowda/incubator-joshua,thammegowda/incubator-joshua,fhieber/incubator-joshua,thammegowda/incubator-joshua,fhieber/incubator-joshua,gwenniger/joshua,gwenniger/joshua,lukeorland/joshua,thammegowda/incubator-joshua,fhieber/incubator-joshua,lukeorland/joshua,kpu/joshua,gwenniger/joshua,lukeorland/joshua,fhieber/incubator-joshua,thammegowda/incubator-joshua,fhieber/incubator-joshua,lukeorland/joshua,thammegowda/incubator-joshua,kpu/joshua