optimize the command help, and add build version in VERSION

Changes:
1. Add a method getHeaderDescription() in Command interface. When displaying command help, will also display the header. It can be description of this command, and can be a example command line.
2. Change 
-        public void process(CommandLine cl,
 -                @SuppressWarnings("rawtypes") Map stormConf) throws Exception;

to public void process(CommandLine cl) throws Exception;

Each command should be free to decide how to parse the command line, instead of we parsing it for the user.

3. Change a version string to a Version class. We add a BUILD number in the Version, so it is more easy for us the track the changes in a mixed deployment environment.