Cleanup dependency and unused files

https://bugzilla.redhat.com/show_bug.cgi?id=1067288
Size of WAR file
before: 102.5MB 
after: 98.6MB
Every dependency with a hard-coded version is another dependency that we have to keep updating, and which may in future be too old for one of our dependencies (assuming they do get upgraded), so we should try to minimise their numbers.

We can avoid hard-coding the org.antlr version by letting drools pull it in as a transient dependency.  This will make it compile scope rather than provided, but it's one of the private jboss modules we shouldn't be using anyway. I'll add a commit to do that.