fix(agent) + chore(fleet): remove redundant RefreshState() from agent startup,
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
Merge pull request #289 from jonboulle/master

Remove double RefreshState on fleet startup. Various other logging and error handling cleanup.