Error handling & backend polishing PR 2: status_app.py

Some small fixes:
* OCD re-ordering imports, don't know why, I had to do it...
* Use Tornado default command line argument parser, this will automatically configure the built in logging. Closes #92 
* Now, only if `--develop` is enabled the files will be watched and reloaded. I think that we should *not* do it in production due to _possible_ performance issues.
```
(master)12:52:39 ~/repos_and_code/status/run_dir (error_handling) ~> python ../status_app.py --help
Usage: ../status_app.py [OPTIONS]

Options:

  --develop                        Define develop mode to look for changes in
                                   files and automatically reloading them
                                   (default False)
  --help                           show this help information
  --testing_mode                   WARNING, this option disables all security
                                   measures, use only for testing purposes
                                   (default False)

/Users/guillem/anaconda/envs/master/lib/python2.7/site-packages/tornado/log.py options:

  --log_file_max_size              max size of log files before rollover
                                   (default 100000000)
  --log_file_num_backups           number of log files to keep (default 10)
  --log_file_prefix=PATH           Path prefix for log files. Note that if you
                                   are running multiple tornado processes,
                                   log_file_prefix must be different for each
                                   of them (e.g. include the port number)
  --log_to_stderr                  Send log output to stderr (colorized if
                                   possible). By default use stderr if
                                   --log_file_prefix is not set and no other
                                   logging is configured.
  --logging=debug|info|warning|error|none
                                   Set the Python log level. If 'none', tornado
                                   won't touch the logging configuration.
                                   (default info)
```