Update to use the kie package structure

As an inexperienced user of Drools myself, I had no idea the previous package format was deprecated a long time ago to this kie package structure. This change-set updates to that package structure and will be compatible with drools >6. Interestingly, the dsl as an additional argument really isn't necessary as we just load in all the files necessary into the kieFileSystem, but I've left it separate for clarity.

I realize you may not be wanting to upgrade yet, but if you want to use Java8 features an upgrade is necessary.
this number could be reduced (I believe the minimum is version 5), but the old stuff was removed in 6.1 .