Merge pull request #285 from jonboulle/master

(bug) Add version to help output
fix(agent): remove redundant RefreshState() from agent startup
chore(fleet): better error handling and consistency
- Import glog as log in fleet.go, as it is everywhere else
- Propagate errors from server.go instead of just panicking
- Handle bad configuration file options better
- Use glog to exit on fatal error, rather than syscalling
remove debugging print line
move RefreshState back into agent