Code cleaning and bug fixes

Some cleaning and fixes including:
- Cleaned up code for ContinuousLR factor which is not supported yet.
- Fixed the well-known Akka non-terminating bugs by try-catch in `DeepDive.run`
- Reduced test output by using --quiet in sampler
- Fixed a warning that happens for a clean `make build`
- Skipped chunking on GP to ensure `make test` work on GP
- Fixed some occasional testing bugs

See the commit messages for detail.
I could not test this easily, since `context.stop(self)` will terminate the test. 

I just experimented and found this is not covered by the try block in DeepDive.scala (it won't throw exceptions to the actor where DeepDive runs, but to some other Akka actor), so it is a necessary fix.