fix timezone info UnicodeDecodeError

[wangyanbn]

ref cloudify-cosmo/cloudify-agent#112:
In agent script_runner.tasks.run ,if an agent locale is not of ascii codeset (such as "Chinese (Simplified)_People's Republic of China", '936'), the timezone info is not utf-8 encoded.This will cause exception in logging (amqp_client.publish_message in cloudify/logs.py) , which will cause exception in local logging with json.dumps.
This method can fix it: when celery app starts, set default locale, and when getting timezone info in logging ,use the correct codeset from locale.

Here is the Traceback:
[2016-05-09 10:08:15,540: ERROR/MainProcess] Task script_runner.tasks.run[84982083-9ef8-4879-add3-da53d623330a] raised unexpected: UnicodeDecodeError('utf8', '2016-05-09 10:08:15.481\xd6\xd0\xb9\xfa\xb1\xea\xd7\xbc\xca\xb1\xbc\xe4', 23, 24, 'invalid continuation byte')
Traceback (most recent call last):
File "c:\users\sys\test_windows_host_2d6ed\env\lib\site-packages\celery\app\trace.py", line 240, in trace_task
R = retval = fun(args, kwargs)
File "c:\users\sys\test_windows_host_2d6ed\env\lib\site-packages\celery\app\trace.py", line 438, in protected_call
return self.run(args, *kwargs)
File "c:\users\sys\test_windows_host_2d6ed\env\lib\site-packages\cloudify\decorators.py", line 126, in wrapper
ctx.task_name, exc_info=True)
File "C:\Python27.11\Lib\logging__init_.py", line 1185, in error
self.log(ERROR, msg, args, *kwargs)
File "C:\Python27.11\Lib\logging__init.py", line 1278, in log
self.handle(record)
File "C:\Python27.11\Lib\logging__init_.py", line 1288, in handle
self.callHandlers(record)
File "C:\Python27.11\Lib\logging__init__.py", line 1328, in callHandlers
hdlr.handle(record)
File "C:\Python27.11\Lib\logging__init__.py", line 751, in handle
self.emit(record)
File "c:\users\sys\test_windows_host_2d6ed\env\lib\site-packages\cloudify\logs.py", line 119, in emit
self.out_func(log)
File "c:\users\sys\test_windows_host_2d6ed\env\lib\site-packages\cloudify\logs.py", line 342, in amqp_log_out
publish_message(log, 'log', logging.getLogger('cloudify_logs'))
File "c:\users\sys\test_windows_host_2d6ed\env\lib\site-packages\cloudify\logs.py", line 322, in wrapper
func(client, args, *kwargs)
File "c:\users\sys\test_windows_host_2d6ed\env\lib\site-packages\cloudify\logs.py", line 379, in publish_message
'message={1}, log={2}]'
File "C:\Python27.11\Lib\json__init.py", line 244, in dumps
return _default_encoder.encode(obj)
File "C:\Python27.11\Lib\json\encoder.py", line 207, in encode
chunks = self.iterencode(o, _one_shot=True)
File "C:\Python27.11\Lib\json\encoder.py", line 270, in iterencode
return _iterencode(o, 0)
UnicodeDecodeError: 'utf8' codec can't decode byte 0xd6 in position 23: invalid continuation byte

[geokala]

Closed: As this PR is more than six months old without having been merged. Please reopen (and rebase if necessary) if it is still relevant.