STORM-414: support logging level to multilang protocol spout and bolt

https://issues.apache.org/jira/browse/STORM-414

@mahall create a PR: https://github.com/apache/incubator-storm/pull/24 , Added logging level to multilang protocol spout and bolt. But he closed it with no reason.

@msukmanowsky create a PR before to apache: https://github.com/nathanmarz/storm/pull/626 , Allow ShellBolts to optionally specify the logging level. But he did not modify ShellSpout and storm.py.

This improvement add optional logging level to Multilang Protocol's log method. And add implementation in python and ruby.
Could we add in some other methods that are specific to the levels.  It think it would make using them a lot simpler. log{Trace,Debug,Warn,Error} You can put in logInfo too, but it feels a bit redundant.