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.
I have noticed the white space. Because _process.getProcessInfoString() return a string with white space at begin and end, so I did not add white space here.

And I think the best way is remove white space in _process.getProcessInfoString()'s return, and add white space in here explicitly, and I have change the code.